do they though? first both of them and afaik all other routers need to reload so for all intents and purposes the routing table is static, you can not add routing rules during the runtime. (Their apparent "dynamism" comes because they sighup or reload the process to put the new rules in place).
Secondly and most importantly they don't error.
Caddy will simply match the last declared rule while Traeffic has a system of priority labels and yet for conflicting rules with same priority again it will match the last one (or even worse a random one).
Both of these are very dangerous because you may realise late (from statistic logs) that you are routing the wrong requests to the wrong handler, and have already missed countless calls that should have gone on the first declared one.
Secondly and most importantly they don't error. Caddy will simply match the last declared rule while Traeffic has a system of priority labels and yet for conflicting rules with same priority again it will match the last one (or even worse a random one). Both of these are very dangerous because you may realise late (from statistic logs) that you are routing the wrong requests to the wrong handler, and have already missed countless calls that should have gone on the first declared one.