There are people who just watch a youtuber habitually - even if the content has drastically changed. There will be a lot of "inertia" for someone that was previously successful as fans hold out that the "next" video will be a return to form.
It takes a long time for a content creator to actually lose an audience (barring they don't do some single gigantic offputting thing) and a lot of YT content is "timeless" - aka you can still go and watch the old stuff.
I found there's three types of way to consume YouTube content people fall into, and I'll cover them in reverse relevancy:
First is whatever the algorithm/friends show them, with no real sense of even the faintest idea of channel loyalty, they just watch whatever they are shown, and don't really have anyone they subscribe to to follow.
Second as channels upload, typically people I see who use this method rather than the most relevant when I will get to next, is these are people who, like myself these days, tend to watch YouTubers who do not have an upload schedule, or they have a monthly upload, or biweekly schedule. This tends to mean they are watching a large variety of long-form content across a rather large variety of channels, because if they did not have a very large variety of channels to watch, they would rapidly run out of content. These are the people who predominantly watch video essays, filling gaps with podcasts, and who are fairly familiar with names like mandalore gaming, patrician TV, ymfah, max0r, razbuten, Curious Archive, Raycevick, tehsnakerer, ssethzeentach, or WhiteLight, to try to restrict myself to the gaming related portion of such viewing. These people likely are so have a small number of channels that do have fairly regular upload schedules that upload shorter videos, typically maybe once or twice a week such as Jim. The video gets uploaded and it gets watched as they scan down their daily subscriber feed. Due to the nature of how these people watch things, They are incredibly likely to become dead subs on a dead channel, or if for some reason YouTube stops informing people of a particular channels videos, They won't notice that the channel is still getting uploads and just become dead subs.
The last group is the one. I think the most people here can understand. These are purely habitual watchers, the type of person who knows who uploads on what day of the week, who watches the new video on that day of each week, even if it happens to be daily, and who essentially have a watch schedule for the week. These people use YouTube truly as a replacement to traditional television, but with a slightly more flexibles schedule. Every Monday they watch ed the new video from Jim along with all of their other usual Monday uploaders, as well as the people who they don't have time to watch because they upload too late on Sunday or they are too busy on Sunday. On Tuesday they have a Tuesday watch list, the same happens on Wednesday, Thursday, Friday, Saturday, and Sunday. Every week they watch their regular individuals. If they have anyone that is bi-weekly they know which week is their weekend, which week is not, If they have somebody who releases monthly, they know who releases on which week of the month. These are the people that likely do not watch anyone that does not release regular weekly content. They likely also complain the most about long form content, citing a lack of time to watch it because they have other things they need to watch. These people tend not to remove people they have been watching for years. It is all about that routine habit of watching. The unchanged routine. They will likely be watching people such as Critikal, zero punctuation, Jesse Cox actually has a regular news show nowadays, and ummm I'll be honest I don't watch people with same schedules often that are relevant here.
I believe that Jim's remaining viewers are mostly people who belong to that last group. Watching Jim is something that they do every Monday, if they don't get to him on Monday, they'll watch him on Tuesday. He releases a steady ticker of content and therefore he fits within their weekly schedule. He very rarely runs much longer than 15 minutes, and these people tend to just not like changes in their schedule. While, they likely consciously don't realize it, a lot of them probably view not watching Jim and unsubscribing as an inconvenience. If they were to look on the right side of their page, they might get suggested someone who was similar enough to Jim that they could get sucked into replacing him with some other channel, but these are the same type of people who, with different politics and a different access to entertainment, would be watching Dr. Phil every week, as well as Going to church every Sunday, after which they would go for tea or coffee at the local cafe. They likely would have some kind of group activity they do every Saturday, and they would have that old friend from back in the day that they met every Wednesday. You likely have a clear idea of the type of person I'm talking about now. The type of person who lives a monotonous scheduled life.
I truly believe a good chunk of Jim's audience are these people. His engagement statistics are low. Jim does not encourage an open discussion of the topics he is engaging with. He is a preacher, a man who stands upon his box and preaches his word as the only undisputable voice. While he has long since thrown out the Banana Republic Dictator persona, he still has that mentality that he is the only authority. So the only people watching him will be out of habit, to receive affirmation of their beliefs, or to have their opinion dictated to them. And well the world is full of sheep, even more than sheep, the world is full of clockwork.