I work with one person that retired from another company. He could only make a certain amount before his pension was penalized by the IRS(I think) until he turned 70. Now, he can work 40 hours. Not sure how old you are but I also think at a certain age, you need to start withdrawing money from your 401k. The financial questions are better to ask a financial or tax advisor.
Generally, I think retirees withdraw their pension, 401k and Social Security and put surplus into savings or other investments.
Retail in general has changed since 2018. You may not enjoy the job like you once did. The dynamics have changed a lot since 2018.
There are several reason why people quit/move on from this company. If you are bored out of your mind go for it. You have to figure out how many hours you can work on retirement hours and not let them force you above that. Because they will if you're not carful. Then you'd loose your status for "retired".
I'd love to retire with this company as well as I spent the first 15 yrs of my job resume at dozens of different places. With the pending merge on the horizon I'm not sure if you want to deal with that.
A lot of people do these kinds of work for health insurance. That and the social time out side the house. (That's why I'm here. Don't need the income from it but it's nice to have.)
If you're bored out of your mind retired you need to rethink your activities. I find people are really only bored because they want to be or they're just not use to doing things other than working. There's more to life than work. I worked with someone a long time where they had 2 jobs because that's all they knew how to do and spend their time.
Enjoy retirement if you do not financially need it. If you financially need a couple hundred extra to help expenses then go for it. If you're officially "retired" make sure they don't work you above the retirement hours limit and trust me it's not many. You will have to be strict with your availablity.
Why would you want to come back after being retired? Figure out what you want to spend your time on. Get hobbies, get active in life (family if you have one) or volunteer if you're bored. There's lots of ways to fill your time. The annoying part about working is its difficult to commit to anything but work. I put my foot down about 32 hrs every other week at least and it's nice to have time outside of work. Not being constantly exhausted.
I know a lot of people who work this job for the health insurance. Just do the minimum retired hours and do not go above that or you risk loosing your retirement status. Do the min hrs required for health insurance and that's it. Remember you left for a reason. If you're bored and financially do not need this don't come back. Kroger will try to work you above your max retirement hrs for the month and push you into full time.