61 y/o here, with mediocre climbing ability. With a lot of hard work I've managed to improve from dead last on every Strava climb segment to solidly middle of the pack. I'm not even a strong climber in my own age group, but we have some seriously strong older riders here. Probably as good as it'll get. So I've fiddled a lot with gearing to find combos that suit conditions and my ability.
I had similar issue with one road bike (sub-20 lb 1993 Trek 5900) and the supplied 52/42 double chainring (Biopace) and 14-28 Shimano 7-speed freewheel. Some steps didn't feel quite right.
The steps felt better after switching to a SunRace 7-speed 13-28. It's basically a fairly closely spaced 5 speed (13-15-17-19-21) with a couple of bailout gears: 24 for when the legs are a little tired and I'm just trying to keep up with a B-group pace; 28 for when the legs are shot and I'm just trying to limp uphill or home instead of walking or calling Uber.
I tried a 38T chainring in place of the 42 for a week or two but it required more double shifting to maintain cadence and speed. And too many chain drops on front derailleur downshifts, no matter how carefully I adjusted the FD. Just when I thought I had it set up for no drops, it dropped on a hill on a group ride this past weekend. Fortunately a friend literally had my back and gently supported my back while I horsed the chain back on (tricky with indexed brifters). After that I stuck with the big ring for most of the ride and my legs were dead after 50 miles of punchy rollers (North Central Texas, no real climbs, just lots of roller coasters with short steep climbs). The 42 is back on for now, although I might try a 39.
But the Biopace rings may defy comparison to circular chainrings. Depending on where the modestly elongated lobes are set on the cranks, the pedal stroke can feel smoother or jerky and surge-y. Seems to vary with individuals. For me, the 52T Biopace big ring feels best rotated one notch counter-clockwise; but the small 42T Biopace feels surge-y in that position, so I'll return it to the original orientation where it felt pretty good. Just a quirk of non-circular chainrings, wouldn't apply to other scenarios.
My other road bike (25 lb 1989 Ironman) has had a 50/39 double and SunRace 7-speed 13-25 freewheel for more than a year and it's just about perfect. Downtube shifters so I tend to shift less often than with the other bike and brifters. With downtube shifters double shifting to get the desired gear can be annoying, so I'm leaving this setup alone. Only downside is there are occasions when I'd like a 28T bailout cog for dead-leg days, but there isn't another combo of double chainring and 7-speed freewheel or cassette with the steps I'd want. The only alternative would be to switch wheels or hubs to get an 8-speed cassette with the same 13-25 steps and a 28 or larger bailout cog.