Honestly, I think Netflix is either going to go under in the next decade or will revert back to only the DVD/Blu-Ray mailing service.
Amazon Prime, I'm not so sure about. On the one hand, they've got all the profit from Amazon's other ventures and have a large library of content. On the other hand, most of the content is behind additional paywalls and a lot of the edgier content is often censored, especially if it involves female nudity.
The streaming services that do survive will be the ones like Disney+, WWE Network, CBS Now, and whatever services that AT&T/Warner Brothers, Viacom, and NBC Universal come up with.
Hulu might also survive since Disney owns the majority of it and can use it to put all the R-rated and TV-MA content they own that's not going to be on Disney+
We might also see some more small-scale streaming services that cater to niche audiences despite not owning their own content. Crunchyroll is an example of this.
Given recent events and controversies, I don't think Crunchyroll itself will survive unless they do a 180 and change their current censorship policies. But if Crunchyroll goes under, a new anime streaming service will inevitably take it's place.
Of course, Troma will keep its streaming services and I'd imagine we'd see similar services from The Asylum or guys like Roger Corman and Fred Olen Ray. Those kind of movies are cheap to make and have a cult following, and much like with Disney's ventures, all of the content is stuff that is owned outright by these studios and creators.
Piracy is on the rise for the first time in years, and I wouldn't put it past more people to run their own pirate streaming services or even online pirate channels.
Hell, I wouldn't be surprised if we see more efforts like NeoToonami.
For those who don't know, NeoToonami was a pirate streaming service that operated kind of like an online TV channel back in the late 2000's and early 2010's after the original Toonami went under in 2008 and Adult Swim massively scaled back their anime programming at the time.
NeoToonami often "live-streamed" pirated episodes of many TV shows that aired on the original Toonami such as Sailor Moon, DBZ, or Gundam Wing.
IIRC, when the real Toonami was revived on Adult Swim back in 2012, the site shut down out of respect and to avoid any potential legal repercussions.
As streaming services continue to lose titles and channel drift continues to get worse, I would not be surprised if some guy decides to say "Fuck it" and run his own bootleg streaming service/online channel that's meant to be in the vein of what certain channels used to be famous for (History Channel with actual history, TV Land as a TV oldies channel, MTV actually airing music videos, etc.)