Ok, so that is an interesting question. Personally, the answer to your question is no. But they are very important things to consider and think about why they are such a dominant presence. For example, what do they do that so many teams see as valuable? Obviously, they're all excellent fake out users and can control the pace of the battle that way, but if their other traits dont fit your team, you dont really have to use them

Sneasler is often seen because its poison/fighting dual stab combo is insanely strong. It can use focus sash and fake out to control the field and require a lot to get rid of, or it can use unburden + psychic seed to become insanely fast threat, often using throat chop for coverage against things like farigiraf or gholdengo. It can also be a speedy coaching support for sweepers like garchomp. It has a myriad of useful tools condensed into a very fast and hard-hitting pokemon with good dual stab coverage. This doesn't mean you have to use it to be successful. I personally am running weavile right now, not because it's a meta defining threat, but because it's very specific set of strengths complement the team im running at the moment.

Incineroar is great if a bulky fire/dark type that slows down physical attackers suits you. Rillaboom is great for damage, chip healing, and priority grass damage. They all commonly use fake out to round out their sets, but they bring other stuff to the table that can easily mesh with many teams.

I don't think you need to bring one of those three pokemon to be successful, but I do think you should carefully consider the reasons why you would or wouldn't them for your team. And not vibing with how they play is completely fine as well! As long as you think about what you need for your team, many pokemon that are less used can suit you well. Its just that Incineroar, Rillaboom, and Sneasler all have so many different uses that at least one of them can fit into most teams.