Green's strengths are powerful creatures with trample, the ability to regenerate creatures (or bring them back from the graveyard), and getting lands faster (called ramping)
Such a permanent cant be targeted by spells or abilities, enchanted by Auras, equipped with Equipment, fortified by Fortifications, or blocked by creatures, and all damage that would be dealt to it is prevented
It has stayed a marquee Pokemon across generations, and its Mega Evolution, introduced in Omega Ruby and Alpha Sapphire, raised its profile further
You won't put any of them into their owner's graveyard
Decks that are looking to enact their gameplan early want access to Check for Traps, but it feels terrible as a top deck
Commander is already a political format where deals are made and alliances are formed, and using a gift to get someone on your side while also giving you a buff to your spell is a good way of playing the whole table