Getting back into (hilly ) road biking in early 70s

I used to road bike a lot in my very hilly community and then stopped a number of years ago because it was just too much hassle as I got older (fixing flats, putting the chain back on if it fell off, feeling unstable coming fast down large hills, etc.)

I eventually bought a Priority 600 which has many feature I really like. The pinion gearbox system is super easy to use and maintain. The bike is stable and easy to ride. And the 6-1 gear range is amazing for hills.

But, the bike is also super heavy, and I stopped riding it much because it is just too sluggish..

I want to get back into road riding, including on some really steep hills in my area, so I feel like I need something lighter. I am pretty comfortable financially so price isn't an issue.

I see there is a new Priority model — PRIORITY GEMINI SMART.SHIFT GRAVEL — that I could consider. It also has the pinion gearbox and is lighter than the 600 but is still heavier than a road bike without pinion. Or I am wondering if I should try a very lightweight road bike, perhaps with tubeless tires and electric gears, or other things that will make it easier to ride and care for.

Basically I'm looking for something stable and easy to ride and take care of and great for big hills for someone who is getting back in shape but will never again have the strength or endurance I had in my 30s.

And I am not looking for an e-bike.

Any suggestions?