On the topic of fun, I do have more comment on this as it had been bugging me for a while now:
There's a very thin line between having challenging mechanics and annoying, extra tedious "work".
The increased weight of repair kits means you need to return to base for repair far more often, breaking game flow making it annoying. Seriously have you try playing a pure AR tin can and watch your gun's durability take a sky dive after every fight? Or play a 3 STR SMG char trying to use trap? Locus? I know they were reduced after much outcry. A certain powerplant not letting you power everything in one go? I know you are trying to drain player resources by making them backtrack to confer a sense of hopelessness and dread - but all these changes and the design philosophy behind them, imho, had crossed this line and ventured firmly into annoying, tedious territory making the game feels like work sometimes and do not, again imho, increase the fun and challenge of the game. This trend is indeed worrying especially with Infusion currently under development and I suspect Styg is using Underrail as a test bed for future system.
Getting a bit off-topic, but I have to concur. Styg has slowly been losing sight of the fun factor over the years. It's the little things that are starting to add up. You bring up some good examples of things that slowly add up during a long playthrough and may not come up in the devs' internal testing. Some annoyances also arise as side effects of well-intended changes, for example preventing armor changing in stealth. It stops the exploiters just fine, but now everyone else has to deal with yet another cooldown, and a rather pointless one at that. Things of that nature.
There is some built-in tedium in the overarching design principles and core gameplay as well and I believe the dev team acknowledges that, but that a different thing altogether. I suspect some things are too big to change even in Infusion which builds on Underrail rather than reinvents it, as I understand it.
Now that destroyor and epeli have posted this, upon reflection, I do also agree a bit with this increasing tedium issue. I've played SMG builds recently and the constant repairing/heavy weight of repair kits leads to some cycle of fighting, and then having long down-time picking up all stuff, recycling it, making kits, repairing own stuff ... ten minutes later the journey continues. But SMGs already suffer from needing so much ammo, why also have the degradation? Other examples have been mentioned by destroyor and epeli. So, yeah, it feels like the game gets more complicated and more tedious in some ways, and maybe Styg and the devs could really look a bit into this from the player perspective for a future update. This is not about power, but much of the nerfs could probably be also achieved differently as in less tedious, for instance with PSI, instead of adding another layer of complexity with PSI reserves, why not just make normal PSI not regenerate automatically. I'm sure this requires balancing but the balancing for new PSI right now seems extensive, too. Same about the nerfs that increase tedium. I love playing the game, but I don't think it should become ever more complex, tedious and focussed on every build doing the same amount of damage at each level.
One quick suggestion on reducing "recycling" tedium: Add a button "recycle all" to the loot window, and if clicking it, the protagonist tries to recycle every item in the loot window they can recycle automatically and then just adds the resources. If the skill isn't high enough, the item just remains intact. That way, when looting, you first pick what you want to keep, then recycle the rest in one click and leave what you can't turn into resources. Might really take the edge off a bit.
Edit to add: or have some sort of repair mode, where you just drag a similar item on the one to be repaired and the dragged item will be scrapped and added to the durability. So if I want to repair my AR, I can use any AR I find and just drag it over it to repair (probably needs some tweaking on the exact way this happens, but this would also speed up a bit the tedium of repairing your stuff)