The biplanes also carried very heavy ordnance, meaning their payload could punch holes into the Bismarck. As others said the AA of the ship was notoriously shit, and these planes despite their speed, were still quite effective against lone ships like a battleship.

I see your point but the comparison just can't match, since leopard 1s are not fast, and modern tanks need to be since they're constantly under fire from AT weaponry, especially the introduction of drone warfare, which knocks out even the heaviest tanks. Leopards 1 are slow, weaponry is small, and their Armor is sub-optimal, they're far too expensive for their qualities too. Plus they're still heavier than Russian tanks which came out during that period. It's important to look at the strategy for these tanks, since they weren't supposed to be used in open fields like Ukraine, they were supposed be defending west Germany from an potential soviet attack. Meaning these tanks would be backed up with massive ordnance support alongside well supplied lines, that is the complete opposite of what you see in Ukraine.

The truth is there's just nothing to send, Germany's stockpiles are gone, all of western Europe are reluctant to send their best equipment. And the US doesn't want to upset the MIC conglomerates by showing their awful performance in Ukraine.