They do have capital requirements (stake needs to be purchased first just like ASICs need to be purchased), just not as wasteful as PoW systems (ASICs life is 6 months and then you need to upgrade to new ASICs, not to mention electricity fees, datacenter rent fees, etc. and all that at an increasingly wasteful rate to compete with other miners).

Inflatable PoS is wrong, no doubt about it. Any inflatable PoS crypto should be avoided. Luckily, there are uninflatable PoS crypto 2.0 technologies, which are not wasteful as PoW.