‘If I were you’ focusses on conditional sequences.
'If I were you ... ' is a traditional English way of making a suggestion to somebody else about what they ought to do next.
English has its own 'way' with conditionals, subjunctives and other structures to explore (as only humans can) how matters might be different.
How adept are you with these? 'If we were you' ... we'd try this Quiz to find out!