Should I replace my kitchen GFCI outlet with an AFCI/GFCI combination outlet?

If it's not required by your local code, then I wouldn't bother. If it is required or you want to do it regardless, then I'd get a AFCI/GFCI breaker which will protect all the wiring and outlets on the circuit (not just a single outlet and any downstream wiring & outlets).

An AFCI/GFCI outlet or breaker won't do much in the way of lightning protection. If that's a concern, then you should get a surge protector for your main panel (which might be something you'd want an electrician to install).

The NEC requires all replacement outlets to conform to the current code, including AFCI and/or GFCI functions, as pertinent. Under the 2017 edition, all kitchen receptacles must have AFCI protection, unless a modified requirement has been adopted, or the installation qualifies for another exception. 406.4(D)(4).

Not only would I not bother, I would not do it, the benefit of arc fault in the kitchen is so minimal it doesn't justify cost or failure rate.