YANBU, OP. I have a solution for you, and others in like circumstances:
Get yourself a decent portable Bluetooth speaker - it's easy to get one much more powerful than any phone speaker. Charge it and take to the cafe; use your PC (or phone, indeed) to play to this speaker.
... Play something you enjoy. (I have used the final chorale from Bach's cantata 'Wachet auf ruft uns die Stimme ...', 'Gloria sie dir gesungen ...' - several excellent performances of this are available.)
Play your music loudly, again and again. After a few iterations, sing along, as loudly as you can.
This makes the point. Although the music may be startlingly beautiful (and actually, if it's Wachet auf..., a supreme human achievement), still maybe not everyone wants to be forced to listen to it over and over in a cafe (or railway carriage etc). But, anyway, it'll easily drown out TikTok, or anything else, on someone's phone or PC speakers.
Why should you be able to impose your choice of listening on others? - You shouldn't. Likewise, then, they shouldn't impose on you. Huh, old lady in OP's favourite cafe? (I'm old, by the way, probably older than her. But you young people can also win against thoughtless noise polluters in this fashion.)
Good luck!