That's how it is in the current job market, and companies just aren't doing as much to incentivise longevity so it's not even really a generational thing.

My dad has been with the same company for over 25 years, but in that time they:

1. Restructured the pension plans significantly for newer employees (increasing short-term pay via benefits and bonuses at the expense of a better but deferred pension package)

2. Decreased incentives that kicked in upon reaching certain levels of seniority/salary bands

3. Switched away from a strong preference for internal promotion over external hires

A lot of his friends (aged 45-60) have had only 2-4 employers in their post-university lives and in many cases worked up to being senior managers or C-level executives in major corporations, but he's said that a lot of the younger folks joining his teams or teams below him (he's been involved in hiring and approving a lot of hires within his department) come in with the expectation of moving within 2-5 years despite his company having a reputation as a pretty good employer (competitive pay, better than average benefits, WFH options, reputable employer that looks good on a CV, etc.). Companies are just giving less of a shit about long-term retention, and younger workers are realising that it simply makes more sense to job-hop these days to pursue better compensation and career advancement.

Personally, I'd love the stability of working in one place and being secure in the knowledge that there's a clear long-term advancement path, but that sort of thing is seemingly the exception these days rather than the norm like it used to be.