To this day, 22 years after I have last used Lotus Notes, it remains the worst software product I have had to work with. It tried to be everything and ended up being bad at all of it.
I didn’t use notes much, but it was a platform ahead of its time, that thanks to IBM’s… IBM-ness was ignored and allowed to rot.
At my previous job they had been using Notes since the company was founded in the early 90’s, meaning they lived through it being Lotus Notes, then IBM Notes and now HCL Notes.
Everything was deeply entrenched - email, warehouse inventory, ERP system, all documentation made in the entire company… just everything.
And this is for a scandinavian company manufacturing high tech devices for telecom and aviation, among other things.
It was… an interesting nightmare, constantly got in the way of any sort of productivity. Definitely contributed to me leaving early