I played on 720p/60fps on a lan where I only brought my laptop. 720p and even below is super playable if you're already used to fucky configs. it's not ideal, but better low res than low fps
TF2 isn't the most optimized title ever, but we are talking about a 14 year old game at this point... I understand that for some, this is a privileged thing to say, but it seems like you are just choosing not to work towards a solution, so I don't feel so bad ¯\_(ツ)_/¯