Experienced older cyclist thinking about first road bike

Hi, just looking for some advice.

I'm in my early sixties, reasonably good fitness & have over 30 years regular riding experience. In all that time I've been used to, in chronological order:
1. A heavy old mountain bike (long since gone)
2.A 12kg hybrid which I still use occasionally
3. A gravel bike bought 4 years ago (Boardman) which I liked but got frustrated by frequent component wear needing gear tuning/replacement so often that it spoiled the experience so I sold it
4.More recently a heavy commuter Canyon Ebike with Bosch mid mounted motor, gates belt drive & enviolo hub gearing (amazingly good, reliable & maintenance free) that I use with heavily loaded panniers a couple of times a week for a 25 mile round trip commute on mainly low or no assistance other than steep hills.

So far, all good, but I still return to my old hybrid at weekends because it is lighter & more nimble when not carrying work stuff like laptops etc.

It has got me to wondering if I might enjoy a better quality used road bike at the weekends, & so I find myself looking at eBay for well looked after lightly used options. I might be too old for taking up road biking but happy to give it a try without spending a fortune on the latest & greatest that might be too good for what I probably am looking for.

I think I am tending towards, for cost reasons, a 105 gearset, aluminium frame & perhaps slightly more relaxed geometry given my age, possibly Giant, Cannonadale, Specialized, etc.

Would welcome any thoughts or suggestions please