Or it can be described as “LineageOS minus” because it lacks the stability of LOS, from my own experience. Bugs are not resolved for a long time, e.g. the integrated K9-fork as email client is not (or was not? I gave up on /e/) able to store attachments. The fix has been postponed to the next release for at least two times. The workaround proposed is: use the upstream k9 for the time being, as the integrated version is horribly outdated. What is the point of having built-in apps that don’t work because they are outdated and won’t be fixed for several months?
Additionally, the microG is (or was?) horribly outdated, so that there were a lot of problems and it couldn’t be updated separately because it is a system app.
These are only two examples. Furthermore, the Quality control is suboptimal, every update there are reports on bootlooping devices (not only FP3).
If you care about privacy in general (and not only degoogling) and are able to read German, I suggest to have a look at the blog-series Take back control by Mike Kuketz and install LOS 17.1 which is working rather nicely. [EDIT: this series guides through the process of setting up LOS a lot more privacy a protecting]
The only “plus” for /e/ which I see is the online storage/backup which makes it more an ecosystem than an OS only. On the other hand, this is not super-capable, so seedvault would be at least as good, IMHO.
You can see, I am a disappointed user of /e/. I think the concept is great but the execution is very poor.