It bears repeating how Oney having a smaller sub-base draws more than the Glumphs.
That's because "Subs" have very little baring of status on YouTube anymore. Sure you get a fancy plaque at 100k subs for your wall, but it's not a big accomplishment in the grand scheme of things.
For example, Matthewmatosis has just over 200k subs. Would you consider his critical input be worth less than say... Girlfriend Reviews? Which at the time of writing has just passed 800k. Not at all.
No matter the size of your channel, YouTube priorities content that has notable engagement per viewer-a-minute, as those statistics present you as viable marketing and advertising space. Additionally as someone who works with YouTube production outlets, it's rather apparent that whoever they've (Grumps) hired to maintain uploads isn't taking advantage/aware of current tagging system or even general word-placement. That said, it should be expected when you hire friends without this type of back-end experience.
For those of you curious: Google has to filter constant phrases, quotes and more to ensure that you are always directed to the most relevant material. It's why when you use Google pictures to search for select content, they've now included the ability to click on related phrases. It's also why the clowns at reddit attempt to mass upvote unflattering pictures of political figures or memes to abuse said algorithms.
YouTube on the otherhand rewrote the ToS and rule set related to tagging material on it's own platform. I wanna say this was back in 2017? Meanwhile, YEARS before that, you used to be able look at what tags a uploaded video used. Clicking the tag would take you to videos using the same key phrases and words, much like the modern day hashtag on Twitter. Problem is people found loop-holes in the system. Tagging your videos with popular channels that are unrelated to the topic, listing pornsites or other lewd aspects etc. It's a system that you have to be highly meticulous with even today. The amount of wannabe e-celebs that tag an upload with JonTron, boobs etc. It's sad but expected.
If you are found to be abusing said tagging system or using no-no words (History, Wrestling and Weaponry focused channels got fucked on this front as they'd often tag terms on a blacklist) you'll either have the video delisted, unable to claim venue or face strikes.
However YouTube in all it's glory are inept at moderating these very guidelines above, just disabled tags from being visible in public and let the bots sweep everything instead. Yay. Alas the only way to find tags now is via third party apps that sell your channel data or right click > inspect and spend ages scrolling for the keywords.
AND WHILE I AM RANTING ABOUT THIS FUCKING PLATFORM
I don't know if it is still the case now, but when you set up a new YouTube account and you state what your main interest is, YouTube would auto-sub you to a bunch of channels they felt would fit. In the case of gaming content, YouTube would auto-sub you to PewDiePie, Game Grumps, KSI, Jacksepticeye, Markiplier, Game Theory and the misc media outlets like IGN and Gametrailers.
It'd legit not be shocked if a hefty percentage of users are completely unaware they are subbed to Game Grumps since your sub inbox is not the default front page anymore
tl:dr: Tag your shit better