I'm a Dvorak user myself since ~2006, and it is good. The main benefit is not the speed, but much less fatigue from typing: you move your fingers far less. This does come at a cost: hotkeys are usually a mess, especially if you have a second language layout (Cyrillic in my case), sometimes working differently dependent on layout, and hotkeys positions are typically optimised for QWERTY. Interestingly, all Dvorak adva…
OSX has a Dvorak-Qwerty-⌘ layout where commands use the Qwerty letters so people switching can keep their muscle memory. It helped when I tried to learn, but I abandoned because I felt like the effort wasn't worth it. I already type fast enough for my needs.
I ended up creating my own Dvorak and Cyrillic layouts, so that Cyrillic layout has hotkeys on their Dvorak positions (in most apps, but not all), and Dvorak layout has some keys like -,= on the same positions as ЙЦУКЕН Cyrillic layout.
Still, I didn't yet find a way to make this layout default for a system: macOS refuses to use one of these on lock screen to enter password, but that's a minor inconvenience.