I am a bit ultra sensitive about parents related things, so I would like to spend sometime and share my 2 cents on this.
Very first thing, stop asking your parents to retire. Because dealing with a major life change like retirement can take a toll on their physical and mental health, weakening immune system and negatively impacting life.
Also asking parents to relocate at your workplace city is not recommended, they built up their social circle where they spent their whole life, and nothing can beat even your 5cr luxury apartment. They may visit and stay with you for a month or so. Take their consent if they like they can stay with you, but DO NOT insist. They might say yes against their will.
What can I suggest my parents to do?
Give outside support even if it's in loss or not making much profit. See if they need a bit financial investment to ease their business. Sacrificing a bit here worth the happiness of your parents. Caution : Avoid "Why" on losses. When on holidays spend sometime with them on their business and partner there.
What businesses they can try?
Have seen parents not changing their business at this age, check if the change of business is required then support them. Seek their suggestion if they are planning to expand.
How can I keep their life fun, exciting, engaging?
Visiting them often is the best you can do. Take them somewhere on vacation. Bring them at your place and talk about your accomplishment.
How can I comfort them to not take stress about work… and take a bit rest in their life?
We often forget "Don't worry" is not remote controlled function. Always understand the stress reason first and try helping them there.
Have huge respect for people who care about their parents. So virtual 🫂.