I walked the Caminho de Tejo from Lisbon to Fatima then the CP from Tomar on the Central route in 2022. It wasn't busy with pilgrims going north, but from around Coimbra there were large groups of pilgrims heading south to Fatima. I didn't stay in many albergues on the CP until I was in Spain, so I don't know how busy they were. Apart from the day I left Tomar, it was rare to see other pilgrims south of Porto during the day.
If by 'popular' you mean crowded, the sections south of Porto weren't crowded when I walked. It made a very pleasant change from the bustle of the CF. Even after Tui, it really wasn't an issue, but there were many more pilgrims at that stage.
I see many people claim different things that upset them. I think most reports are real, but it really is up to you to deal with these. It seems to me more the state of mind that you bring with you that will make this a worthwhile camino for you.