It may make sense if there is some kind of bonus like hitting diamond (and someone will realize a lot of benefits out of diamond over it) or a big amount of points for a minimum spend, but for just 3 pts/$ I don't think it's worth paying the convenience fee. I don't even use my Hilton card on non-bonus everyday spending there are other cards that get me a lot more value than 3 Hilton points/$.

I did pay the conveience fee a couple times on taxes. It was before I really got into MS and used to fly southwest.

When Southwest had their old RR Program paying the convenience fee got me enough spend in to get enough points for a companion pass a couple years. Paying $300 in fees for a companion pass on southwest was well worth it, especially seeing those credit cards points were enough to get me another free ticket and I could use the CP on those so it was like getting two free tickets on southwest for around $300 in fees