And they used to have a shuttle from Brussels. Not sure about this year though...https://www.brusselstimes.com/49118/rock-werchter-bus-will-transport-festival-goers-to-brussels-daily
I always take it as a positive when I'm at a show abroad. Good opportunity to see my favourite artists in a smaller setting without being elbowed in the face by people trying to get to the front. Even when it means getting up way too early. I guess in this case it's indeed a niche vs mainstream festival thing.
It's a Belgian festival, so you have to take into account a band might not be as popular over there. I remember a discussion a few years back about Wolf Alice not being in the Barn. but on the Slope stage. In the end there was plenty of room at the Slope.
And this is 2017, but should give you an indication about the location of bus stop in Zone A (neer the Hive camping). Would not recommend driving yourself. Parking near RW are full with people camping so you'll have to walk a long way. And I'll take a long time getting to the parking in the first place.
this is 2018 and in Flemish but with google translate it should give you an indication about location and shuttle times https://www.delijn.be/nl/gemeenten/vlbr/werchter-2018.html
Lowlands is great, but might be very difficult to get tickets. They sell like crazy in regular years. Next year they will give out pre sale code to those who had tickets for 2021, so will be even more difficult to get them in the regular sale.