Historical examples should be used with caution to try and predict a future career-path, as circumstances are so dynamic; e.g. the general state of the economy, management policy, fleet size, not to mention "events, dear boy" such as war, COVID, 9/11, etc.
For what it's worth, here are the paths taken by four BA pilots who joined as DEPs in 1997 (all timings approx):
1. P2 744 / 6 mths / P1 737 LGW / 2 yrs / Trg Capt 737 / 5 yrs / Trg Capt A320 LHR / 12 yrs / Trg Capt 787
2. P2 744 / 12 yrs / P2 777 / 7 yrs / P1 777
3. P2 744 / 19 yrs / P1 787
4. P2 744 / 14 yrs / P1 A320 / 4 yrs / P1 787
So, 20 yrs to a LH command seems about right.
As far as salaries go, I think BALPA publishes the scales, but in 2020, LH P1 after 22 years was a basic of £177k with about £20k allowances on top, all gross before tax.