Replacing an ageing PC

It appears to me that the way forward is not to buy a new pc plus all the attendant operating systems/software etc..
Is it not possible to have a new PC that exists in the ‘cloud structure’?
I envisage a bare bones device that enables me to connect to a cloud computer with all the software I need in it.All I would require is a keyboard. a mouse and a screen (which I already have) and possibly a hard drive memory – and what else?
Any ideas?