What does "summer crowds" mean in Lofoten?

Planning to spend 3-4 days in north Norway... originally considered Lofoten, but after reading some posts having second thoughts.

Now wondering if Senja wouldn't be a better choice for us. We are 2 adults, like short hikes and long drives, in relative solitude during the day but don't mind it lively at night. Senja would be more convenient as Tromso airport fits nicely into our itinerary, Lofoten would have be reworked but still doable. We would stay either at Hamn i Senja or Henningsvær (both booked).

When people say, Lofoten is very crowded in the summer, what exactly does it mean? Traffic jams on the tourist routes? Long lines at ferries? Packed trails? Booked out restaurants? Or something lighter than that?

An alternative might be to visit both, with 2 nighs in each and a long drive and a ferry Andenes - Gryllefjord, which could be fun.

Thanks!