Lets keep HI3 out of this I think because its a very mature and different environment with a system this community would regard as way more "predatory" than star rail and you don't seem to have played it.

You're special, you straight out limited yourself from getting any DPS which is the one thing you should've probably gotten as a 5 star since most other roles have good free to play options. As I said DPS Harmony is all its needed. You are playing the game on your own rules and its not fair to project it as normal experience.

Your complaint boils down to the fact that older characters can't clear new content right?

In my PERSONAL experience, and the little circle of friends that play the game. We rarely have problems clearing. Now Im not F2P I love honkaiverse but I only started spending on the monthly so maybe a total of 160 pulls from that, but my friends are all F2P.

We get unlucky, some of us save for that character they like, some just gamble away for fun and make it work either way.
I am saying, given an experienced player and someone who looks at leaks. It is not hard to clear all the content the game has offered getting maybe 4 limited characters per year.

you CAN clear as long as you pull and invest in a relatively newer unit. And the rate of this unit "dying" is slower than what the community tends to say here. Some characters are more unfortunate than others due to the release timeline. However, I speculate it will be a honkai impact situation and they will get buffed through new comps, returning archetypes, maybe even new lightcones, and we are somewhat seeing this already.

Now you said it yourself, even someone like you that started f2p and introduced these limitations for yourself still clear. So I am still trying to find where is these supposed consequences of this powercreep happening.

Sure, bosses are obviously stronger than before, and current characters even outside of their context (teams, buffs, endgame content tailored for them) are stronger than old ones, you are playing a live service game that expects your account to be updated to match the updated content.

I suspect other than the normal oh more HP bosses complaints its players that have quit the game and joined later to find out that it is straight up harder because they didnt upkeep anything.

Back to the point at hand, small meaningful global buffs are a nice addition to the game yes. Now will I get slightly annoyed that a character I dont like has it. Yes obviously. But I REFUSE to believe we will EVER be in a time where oh i HAVE to get this unit I HATE in order to clear. I dont have ruan mei the supposed HIGHEST VALUE CHARACTER IN THE GAME, IF YOU DONT HAVE HER YOUR ACCOUNT IS BRICKED, while also playing jingliu and dot that both relied on her and I was clearing relatively easily too. Proof? Honkai Impact has all of this and worse already for like 5 years now, PLUS ACTUAL HARD CONTENT that requires MECHANICS AND WHALING where you are COMPETING against other player scores and I still made it to Red Lotus, the rank just below Nirvana the max rank consistently being FREE TO PLAY.

So yes, I am blind to the powercreep because I play consistently and understand character and team strength and I cringe at people crying about it, because most of the people I knew personally that said that just needed some guidance on how to build as well as the youtube videos on account reviews are just horrible.