Teambuilding is a luck-based, uncompetitive strategy that brings every match down to the unpredictable probability of what the opponent has chosen. It's been a problem since day one, and every battle is worse than a coin flip. A coin flip at least has statistically equalized odds. When it's a team of 6 against possibilities of over a hundred times that, we've been ignoring the obvious problem all this time. Opposing teams are impossible to counter 100% of the time no matter what we actually incorporate into team designs. It is made even worse by the undeniable variability creep from generation to generation, not just in Pokemon themselves but in movesets. To this end, we need to take action to ban the toxic influence of these factors that have been subverting any and all attempts at a healthy metagame. Thankfully, we have had a model period in the past, during better times, that we wish to replicate. The exemplar we speak of is known to the true fans of Pokemon who know what a good meta environment looks like. And I speak of course about Wobbuffet. All Pokemon besides Wobbuffet, including Wynaut, are henceforth banned from the Showdown simulator altogether. We, I believe, have at last developed a gameplay experience that captures the spirit of what Pokemon battling should be like.
<Edit: TM20: Safeguard is now also banned due to having been exploited as a loophole.>