Reasonably true, except that in reality people move between DAWs rather rarely. The real world lock-in is quite high, even if the theoretical lock-in is lower.
The other half is because pretty much every DAW has some non-standard plugin/scripting system: Ableton with Max, Reaper with rJS, Bitwig with The Grid, etc. If I moved away from Ableton, I'd lose my M4L plugins/patches.
Standards for opening projcets cross Daws will help, I think, but the biggest 2 things that will motivate change is MIDI 1.0's slow death so that more is possible without strange, custom systems and CLAP, again for more-or-less the same reasons.
Push is not locked to Live at all. I wrote the support for it for Ardour.
Osmose uses MPE, just like other MPE devices, and it's not weird, its actually quite elegant.
Sysex was always meant to support device specific control, so of course it's "strange". And almost every bit of MIDI software "deals with" sysex in some way.
"Pretty much every DAW has some non-standard plugin/scripting system" - there is no "standard" scripting system, and in fact most DAWs have no scripting facilities at all.
CLAP offers nothing that existing plugin APIs do not, except for modulation ala Bitwig, and since no other DAW so far can do modulation like Bitwig, the value proposition here is low (not zero, but low).