Poker players overthink things. You don't really need a special bankroll of X buy-ins unless you're playing full-time.
I agree, that not everyone need a bankroll. However if you play mainly for profit and play almost every day, even its not full time, because you have a job or study to take care of, then you do need a bankroll. This is because, you dont want to end up in a situation, where you can not play again, before you get your next paycheck and are able to take money from that and put it into poker.
And you also dont want to be moving up and down constantly. Like maybe you take some "shots" at $22-55 MTTs without having a proper bankroll for these games, and it does not work out, so now you only have $50 left to play with for the rest of the month and have to move down to $1 MTTs. Then its significantly better to play for instance $5.5-11 MTTs the entire month, if this is, what you are bankrolled for.
With that being said your entire poker bankroll does not need to be sitting in a poker account. If you know, you will be able to deposit another $200 or $500 any time, it might be needed, then its fine to consider that money part of your bankroll, even its sitting in a regular bank account. Or you can have your bankroll distributed among more than one site. There is no need to have a separate bankroll for each site, as some people think.
Just decide how much you can spend on poker per month from your paycheck, and play the most profitable or just the most fun game.
If you are mainly playing for fun then absolutely 100% yes. Everybody talk about bankroll management, but far more people should instead be thinking about making a poker budget, if for instance they mainly like to play some MTTs in the weekends and dont play on working days and perhaps not even every weekend. Or if they are new to poker and have no track record to prove, they are winning players.
Don't get stuck in small, high-rake games trying to build some abstract bankroll before moving on to bigger games.
I agree, that far to many people are obsessed with the idea of "building a bankroll from nothing", and this keep them stuck in
freerolls and penny games, that are neither particularly fun to play or particularly good for learning and improving. Most people would be far better off making some reasonable deposit and then go from there.
There is also nothing wrong with adding to your bankroll from paychecks gradually. Like maybe you feel, you are ready to move up skill wise, but you still lack another $200 to do so. Then just take that money from your next paycheck and deposit it, if it wont be needed for other purposes. Some people have this idea, that you should only deposit once on each
poker sites, and this is also pretty silly.