We need three things here on Steam Client, so our interactive experience using it can gets better.

We should be able to do more than link our Steam Account with youtube and have our uploaded videos from our youtube channel displayed there on steam, on the videos profile section. Would be good too, to have the possibility of display videos here on steam with that profile section, that we liked using our youtube accounts, not just the ones made by us.
I don't understand why there's such limitation.

We also need some feature that makes possible of hiding certain titles that we may have on our accounts from other ppl eyes. I think a good way to do that, would be having the option to mark a collection with a NSFW marker, so the titles added on such collection would stay hidden from other users like friends or the general public.
I say that, since i have heard more than one time from a friend, that they have their profiles on private mode due that, since they don't want others looking at what they have on their library, so to hide some games, they must hide all of their games, kinda sucks and makes difficult to know what games they have in common with you.
So such option would be quality of life improvement for the platform indeed, wouldn't be a too complex solution, but a simple one.

EDIT:
Would be a good option for that too, if we have a improved gallery with multiple options to control visibility, no matter how you tag them (if its visible for everyone, only for people logged in steam, only for specific users like friends, or 100% hidden from public and private, that last option its the one I would choose xD).

We need a option to save the configuration of our profile, I mean, the wallpaper you are using, the profile picture, avatar frame, background, badges displayed, everything.

Like these games who have their own customized profile that you can select and set it by one click ( for example Carrion, Civilization VI, Cyberpunk, Outlast, Residente Evil 8, etc.).

I say this, because a lot of people, like myself, enjoy picking a theme and making their own customization, using badges, achievements, items displays, etc.

If we have such option, would be a lot more easy setting things up if you want to change the theme, but after some time you want to have the old customization back, but you can't remember the way you set it up back then.