I remember getting Hu Tao when she was just released. She was (and I guess still is?) one of the best characters. But I didn't have the roster to really play her to her full potential. So it's back to the loot crates to try and pull other characters that synergize with her and help her reach her potential.
There's nothing in the main content that requires you to have a 5* character/weapon, even though it's certainly easier with them.
If the critique is "I can't maximize to the absolute highest stats without paying" -- then sorry, I think that's an attitude full of false entitlement.
Heck, look at this frickin video about how they produced the Liyue OST: https://youtu.be/pFrKZxStL_U They commissioned a massive Shanghai orchestra team to produce excellent music. And we get all this amazing stuff for free.
The game gives you a free character of each element to handle the necessary synergies.
There's a difference between "severely hampered" and less effective at end-game content.