Kindle is only locked if ya buy ebooks from Amazon. No Kindle has ever been locked for me, because I've sideloade all my DRM-free ebooks, for the last 20 years that I have been using ereaders, including Kindles.
The key here, and this is for any ereader, is never buy an ebook using anyone's specific DRM. Ever.
I think some people are misunderstanding the "locked" Kindle part. Those of us who are inclined to sideload and hack anyway, don't care. And the normies never ever transferred anything via USB anyway.
You can buy a brand new Kindle today, and still load your own books on it. That hasn't changed at all.
I don't support Amazon's take on this, but Grandma Jones likes reading the latest cozie mysteries on her Kindle, and she buys them from her Kindle directly anyway. She doesn't even have a USB. So it's hasn't changed for her at all either.
TL;DR: Nothing has changed for me. DRM is the real evil, and lots of places besides Amazon try that shit.