If you're using your certification to qualify for a professional or volunteer position, then they usually defer to the expiry period set by the issuer of the certification.
In my experience, basically nobody gets any first aid practice, in between re-certifications. And these are perishable skills, so I wouldn't trust in the ability of most people to execute anything complex after even a year has gone by... But that has to be balanced against the cost of re-training. WMR is usually an 80-hour course (IIRC) and re-certs more like 30-40? That's an absurd time investment for most working people.
80h, that's almost one's whole summer vacation
I hope that more of these courses can evolve into a hybrid online model, where you can use distance learning to spread some of the coursework out, ahead of time.
I wouldn't try something complicated like a traction splint unless there was really no other option and possibly even then--not sure they even teach it in WFA any longer. But, for the most part having a weekend class to refresh a lot of first aid isn't a bad thing even if you don't practice it all the time, may have forgotten some of the details, and maybe your splints aren't the world's greatest. But so long as you're cognizant of your limitations having some even somewhat stale first aid training is probably better than having none.
[Of course, if you act like your 10 year old WFR or W-EMT cert means you're qualified to charge in and take over because you're "certified" that of course can be an issue.]