Why are most NEXT JS apps so slow?

Every time I visit a website and I click a link and get a 2 second delay for each link I always think "This must be a next app", I check the code and see it is.

I assume server components waiting to fetch the data but its super slow on initial load (after that it's fine).

I see some optimised next apps that are fast on initial load but 90% I have come across have always had this slow load. Noob devs or bad framework?

What's the go?