I think it matters more to US-based golders who play stroke play.
Par doesnt matter as much in match play.
On the contrary, it is in strokeplay that par matters the least.
In strokeplay the aim is to complete the whole course in as few shots as possible. The number of shots taken on any one hole is irrelevant - it is only the total that matters.
In pro tournaments the only significance of par is as a yardstick of relative performance of players at different stages of their round.
Par matters in matchplay in that it contributes to the handicap or stroke index of holes on the cusp of par. A long par 4 will have a low number; the same hole redesignated as a par 5 will have a much higher handicap or SI, leading to a very different distribution of shots in a match. This might or might not make a significant difference to the eventual outcome.
Where par really matters is in the Stableford competitions and social games which make up a large proportion of golf in the UK. The whole scoring system is predicted on the par of each hole.