Most senior engineers at organizations require a significant amount of coordination and people-skills. If you're not managing a team, you're definitely managing the relationship with your manager and coworkers/project teammates.
Thats totally fine for folks who thrive in this kind of role. However, it does take away the ability to grow your career if you want to keep developing software. So for example, if you program for 20 years, and keep improving during this time, you would expect to be rewarded with some career progression for the progress you've made in years 10 - 20.
But as it stands, these days, if you run into someone who has been programming for 20 years, you can assume their career has mostly stagnated, and might even count them off as a low performer because they failed to grow. So it's almost a self fulfilling prophecy - staying a "true" IC has no growth, and therefore there is an incentive to just sit back and stop growing.
Yes, but you're not managing people. It's a lot of collaboration and leadership, certainly, but not doing any of the HR-adjacent bureaucracy that comes with being management.