Often times yes!
Not only as a wallet but like an investment for the future. I am proud to say this that for the past 8 months that I have been on this platform, I haven't invested any real money yet on Steem. Whatever rewards I get, I use most of it to power up into my account. So far I already have 750 SP on my account without investing anything.
And I am not planning on powering anytime soon. For some this might only be a small amount but I see it as a slow investment for the future. With how hype SMT's are and how revolutionizing the blockchain technology is, I really do think that this small wallet of mine will start to make a difference years from now.
Depends on what sort of wallet you are talking about, If you mean my IRL physical wallet, no, I barely use cash these days but if you are talking about crypto wallets, they actually ARE small banks! With Steem you even get better interest rates than what you would get at any bank right now! I think the current interest rate is around 8.50% yearly!