It sounds very familiar here that the mark of a senior is to have continuous pressure against getting anything done and then still getting stuff done.
One part of it is that if you’re capable in a platform, you should be able to get out the same amount of code in a fraction of the time.
I’d add glibly: if you’re getting stuff done, maybe you’re not a senior?
https://swizec.com/blog/why-senior-engineers-get-nothing-done/