They are completely worthless for the reasons you stated. A few months ago I connected with a colleague from ~ 15 years ago. He endorsed me for skills that weren't even invented when we worked together.
Recommendations are even more unreliable.
Case in point: A manager who was on the same level as my direct manager contracted an 'Architect' to come up with a high level estimate for a big project. The guy basically drew pictures in Enterprise Architect for 6 months and barely interviewed any stakeholders or technical folks. I was in the meeting where it was decided that it was a worthless exercise and big waste of time/money. We let him go right after he turned in the project plan and scrambled to redo the work.
The manager that hired him wrote him a very positive, over the top, gushing recommendation on LinkedIn.
I don't know if it was 'quid pro quo' or just the manager trying to save face but it definitely showed me that they are worthless.
Recommendations are even more unreliable.
Case in point: A manager who was on the same level as my direct manager contracted an 'Architect' to come up with a high level estimate for a big project. The guy basically drew pictures in Enterprise Architect for 6 months and barely interviewed any stakeholders or technical folks. I was in the meeting where it was decided that it was a worthless exercise and big waste of time/money. We let him go right after he turned in the project plan and scrambled to redo the work. The manager that hired him wrote him a very positive, over the top, gushing recommendation on LinkedIn. I don't know if it was 'quid pro quo' or just the manager trying to save face but it definitely showed me that they are worthless.