Why is Blitzcrank perceived as so strong, right now in particular?

This question is probably pretty obvious to answer, but I've mained fill since season 4 and have been quite familiar with blitzcrank support (especially with "fill" in DQ being Support 2.0 now) the last 3 seasons, which probably clouds my perception of it because of familiarity bias.

Blitzcrank is in or very close the top 10 bans by % in gold and up now, and I've always understood that his banrate and ability to tilt players has always been high (In no small part due to his Rocket Grab).

But why is he so strong NOW, in particular this last 2 seasons?