The generator service company now says after about 5 years that I need surge protector installed for tbe main switch thing. Does that sound right?

You should have whole house surge protection on the main panel anyway, really. Not sure outside of that. And for what it's worth, I have said protection and have lost equipment anyway due to close lightning strikes. Not sure what the end goal is but there is no such thing as surge protection for close strikes.

Our local lightning guru is Dr. Heller, teaches at Blinn in Bryan TX.
Also a master electrician can advise.

We have wall outlet SPs on the Washer & Refrigerator
then a SP power outlet that is renewed every year on the septic pump
b/c we were told "once struck, that's it", so protects only once and there's no red light thata comes on when it's "dead'

So guessing they are correct but maybe annotate as "every 5-years or after every lightning interruption" if you are aware of any.

Let's hear from those in-the-know now .......

Based on how you asked the question, it seems that you don't currently have surge protection, and the company is suggesting that "now that it's been 5 years, you need it". This sounds like an upsell tactic, and has no factual basis. Shady as hell and I wouldn't have them do the work, and I bet they'll upcharge you. If you really want to add surge protection, which is a nice, but unnecessary feature, then get an electrician to do the work for you.

If for replacement, whole home SP typically has some kind of diagnostic light that will tell you if it needs to be replaced. Look for that first and follow the instructions which should be right on the device. They do wear out, but not usually just a time thing and sort of makes you question their intent.

RE: the transfer switch; somewhat of a marketing spiel. Over time the contacts in the transfer switch arc every time they are operated and there is some pitting in the contacts. The pitting causes the generally small voltage spike when the contacts are opened and closed to start increasing in magnitude (voltage) over time. If the pitting is bad enough you can get some pretty large transient voltage spikes everytime the transfer switch is opened and closed. I've been on some commercial and industrial sites where every time they do their monthly generator test and transfer to and back from the generator to utility power they lose a good number of lights and maybe occasionally some unprotected electronics. The simplest solution is transient surge protection to turn the excess energy in the spike to heat or send it somewhere else (like ground).

Keep in mind most whole house surge protection is rated for large lighting strikes but will let between 1000 and 1400 volts through it on the bottom end. 1000 to 1400 volt spikes over time isn't good for sensitive equipment with circuit boards, etc. Your typical strip transient surge protector will have a maximum voltage rating it can handle before it is fried somwhere between 800 and 1600 volts depending on price and quality of components. So the idea is to make sure your whole house knocks the big stuff down to a level the plug in or outlet device can handle without being fried. The jargon used in the industry standards is Category 1, 2 and 3 when you start looking at the ratings and what they will handle on the top end and what they let through on the bottom end.

Thank you Lone Stranger.

I don't know anything about electricity - so bottom line - should I get it or not. Please advise.