[bruce511]

There are a number of reasons why a job in the hand might be worth two in the bush. Each situation is different though so ymmv.

Firstly there's more to a job than just pay. Some places are better to work at than others. Perhaps it's team dynamics, geographic location, remote or office, good or bad office etc.

Some financial perks improve with length of tenure.

Long-termers tend to have more job security than newbies. First in, first out when positions are cut.

Fewer, or more, responsibilities. Things like being on-call over weekends.

Seniority often comes with non-financial perks that aren't monetary, but make life better. More flexible working conditions. Better parking. Work from home, and so on.

None of which stops people discussing pay with their manager. Which is a Lot easier to do than switching jobs.