Even the oil change was a pain. I had to quite literally crush the dealer oil filter and break it off in pieces with a pipe wrench because it was shaped in such a way you needed a special tool to get a grip on it. I called the dealer, the tool was $180 and would take 3 weeks to ship. It only worked with Triumph brand oil filters (probably white labeled semi-custom K&N's) and they wanted $60 for a filter (vs. $14 for a K&N at the local bike parts store).
Even my best universal clamps + duct tape + sandpaper couldn't hold a grip on it. Several trips to the local auto parts store trading wrenches back and forth until I said fuck it and went to Home Depot. Lucky for me a K&N oil filter fit exactly (dummies still used a standard thread for the oil filter port)...otherwise that would've been somewhat hard to explain.
I was considering triumph as my first bike but after reading this its a hard pass.
To your knowledge are there any brands known for being DIY friendly on current models (read being able to provide/sell offline service manuals)?