Data is the worst bottleneck IMO.
Least with HGE stuff you can just cruise around until you gather what you need.
In a "good" HGE system, you can find a HGE at least once every couple of minutes.
Even in a less successful system, you'll get a HGE every 5 minutes.
1 HGE gives you 3-5 drops or 9-15 mat's.
You're collecting at least two mat's per minute searching for HGEs.
Compare that to what's required to collect top-tier data, which mostly comes from base-runs or missions.
If you're getting it from missions you have to rank-up with a faction until you start getting the right sort of missions.
Then you get 1 or 2 missions on the board which supply you with 3-5 mat's, take around 30 minutes to complete and potentially incur fines/bounties which need to be cleared.
And then there's base-runs which (IIRC) now provide one mat', take around 10 minutes and almost certainly incur fines/bounties in the process.
Looking for G5 data, you'll be lucky to pick up 1 mat for every 10 minutes you're playing.
Which makes it 20 times more painful to collect than stuff from HGEs.