I'm in North America. Today, people answer "Thank you" with "No problem."

'He is taller than I'. However, I would say 'He is taller than I am' OR 'He is taller than me.'

'He is as tall as I' sounds just a bit put on. However, I'd never even consider correcting someone for saying that just because I'd rather hear 'He is as tall as me.'

The purpose of the spoken language is to communicate. Either will do, but I'd say me, not I.