What came to mind isn't really topics, it's format - though might help you with fine-tuning topic selection on the day.
What I might do is give two or three examples of computer frustrations, get a show of hands for who's experienced those ones, and then invite the audience to name frustrations they've had themselves (or where they've tried to help a relative). Like "think of a time when you were trying to do something on your phone or on a web site and you couldn't get it to work".
I would gather the crowdsourced examples on a flip chart or similar, and refer back to those examples to illustrate principles.
When on enshittification, could also ask for examples of "this used to be easier than it is now" or "just as I'd got used to it, they put the price up".
It's harder to prep for that semi-crowdsourced format than if you know exactly what you're saying in advance, but has the advantage that you get a sample early on of what they've already noticed / where their level of understanding is. Then you have a chance to adjust your level of complexity on the fly, & know yr not talking over people's heads.