Lastly, I just LOVE the aesthetics. Even XFCE could not resist the allure of "improved" themes and also ended up welcoming CSDs.
For me personally, the biggest thing holding it back from becoming a daily use computer is the lack of a really good web browser. WebPositive has made great strides as the native browser, but it still has a long way to go. There are ports of other mainstream browsers but most are incomplete or unstable.
I sorely miss the era around 2000-2001 where I used BeOS successfully as a daily machine, able to browse the Web, access email, do document management and creation (word processing and spreadsheets), photo editing, music production, and video editing all with native-to-BeOS software. It transformed my Windows 98 machine from a slow, clunky, stuttering mess into a computer that felt like it was from the future. Nothing since has come close to that level of technological Nirvana.
At the time I last tried there was no support for USB Wifi, so using a trusty TP-Link wasn't an option.
Amiga.
[1]: https://medium.com/@probonopd/my-sixth-day-with-haiku-under-...
It's a real desktop OS, with a UI meant for a keyboard and a mouse. A rarity these days.
BeOS was an interesting OS, 20 years ago, its time is due, API frozen and just like Oberon and Amiga, only usefull for nostalgic purposes.