Well, it's just... do you (generic you) need or even really want $30 of new stuff each month? Let's assume that's really what's going to happen.
If you don't care about (or actively dislike) content related to a particular setting, or you have no particular need for yet another rogue archetype, but that's what they want to give you, you're stuck paying for it. It's not like now where you can decide if you want to spend your money on a new book. You very likely won't be able to choose to not get the content and pay less that month to keep your access to the tools.
And honestly, why you (specific you) may have no problem with $30/month, a lot of other people will have problems with that. That's a lot of money for many people (including myself). Especially when I can game TotM-style in Discord, or in person should my group go back to that, for free.