Dude, the mental gymnastics are insane.
Trapinch itself is not "uncompetitive". Sheer Force / Hyper Cutter Trapinch is useless as all hell. Until Arena Trap is thrown into the mix, making it viable if Dugtrio is gone. You know why? Because the God damned ability is the issue.
You CONSTANTLY cherry pick and avoid the otherwise blatantly obvious. I, as well as most others, am not saying Diglett nor Trapinch the Pokemon are the issue. I have constantly stated this. What is the issue, is Arena Trap. Regardless of who the ability is attached to, it removes, not reduces, player choice, which is inherently "uncompetitive", which has already been addressed.
You keep gish galloping and avoiding the blatantly obvious. There's no discussion to be had if you constantly refuse to acknowledge what people are saying and instead cherry pick in a feeble attempt to try to get the precious "gotcha".
It's the combination of Dugtrio and arena trap that's really the issue here. Trapinch plus Diglett are either too slow or too weak to be consistently effective in trapping ou threats. What is Trapinch going to trap with base 10 speed and 45/45/45 defenses? Diglett is a bit more effective but with base 55 attack it will be harder to trap that aren't 4X weak before it gets killed itself.