To expand on what George just said.
I’ve written about 15 apps with JQueryMobile (JQM) with users totaling about 3 million so I know it quite well.
The guy developing JQueryMobile and the guy who did JQueryUI (JQUI) were constantly butting heads. Finally the JQM lead was “over it” and left. This was as JQM 1.5 was entering beta. Since he left, all work on JQM has stopped and the JQ people are advising that no new projects be started using JQM. JQUI contains a lot of the widgets found in JQM but, frankly, they look antiquated and they don’t follow either the iOS standards nor Googles Material design.
Beyond that, some of the very basic functionality in mobile apps, while doable in JQM, is like pulling teeth with a tow truck hook… you can do it but the results are gonna be U.G.L.Y.
To add insult to injury, google is not approving apps that are based on JQuery 2.x or even 3.0 because of security issues. You must be at Jquery 3.1.x and JQM will not run with JQuery 3.x.
(UNLESS you install 3.1.4 AND the migrate plugin… then it seems to work.)
On top of all that, the guys who supported JQM in their forums were just jackasses… a real sign that they’d been doing their jobs just way too long (hardly a response is made that doesn’t include either a left handed or out right insult).
The frameworks I have looked at (because I have to migrate all those custom apps I’ve done for people) are Bootstrap, Vue, Framework7. I could just never get into Bootstrap. Vue looks a lot like Framework7 (or v-versa) and is really designed to be used on both desktop and mobile apps while Framework7 is just for mobile apps and has widgets that the others don’t.