Then they released a preview of a re-design which also broke all extensions. That's arguably fine for a preview, though a bit concerning. Many were raising alarms at this point.

Then they released the re-design to the stable release, with still-broken extensions. This pretty unambiguously is "a mess", if not earlier.

Then they released built-in support for a couple dozen Mozilla-selected extensions (uBO included, I believe). This is still a mess, and rightfully raises a few eyebrows.

... and we're still there now, after over a year of "this will be fixed soon". I believe you can install nightly + manually tweak config and still install other extensions, but Firefox for Android does not support extensions right now. That's A Problem™, and not a good sign for extension-longevity that it was ever allowed out of preview. It broadly implies extensions are very low on their priority list, which is concerning, as extensions have been the clear leaders on preserving privacy and user control in general. Browsers overwhelmingly follow popular extension behaviors, not the other way around - cripple extensions and you also cripple advancement and experimentation.