There arent very many scenarios where youd want to skip the ability, though
2020-04-17 If you reveal a companion outside the game, for as long as it remains there, you may pay any time you could cast a sorcery (that is, you have priority during your main phase and the stack is empty)
Tasha's first ability is a +1 that draws a card and exiles up to one instant or sorcery from each opponent's graveyard with a page counter on it
As a point of comparison, in Goldin Auctions' December Holiday Auction, an SGC Gold Label Pristine 10 "1 of 1" Charizard was sold as the first lot for $360,000
This doesnt even begin to get into what Lurrus could do in a combo or artifacts deck with cards like Mishra's Bauble and Lotus Petal that put themselves in the graveyard or are interested in getting artifacts in the graveyard
It's important to stack the triggers so that the Goblin Cannon doesn't sacrifice until you have pumped enough damage into it