I think I came across a crashed ship once, there were sentries though and when I got close I was warned of tresspassing.
That is not the same kind of site as the crashed Anaconda sites at Orrere or Koli Discii, which just sit there unguarded waiting for you to truck around with your SRV scooping up the mats!
Last year, in the Type 8 update, FDEV buffed sources of engineering materials precisely because they want to improve what you are calling "unbearable grind". The patch notes include:
Increased Material availability/payout at Grade 4/5 farming locations by increasing sources of materials and in some cases payout per source.
These buffed "farming locations" are High Grade Emission signal sources in space for G5 manufactured materials, the Jameson crash site at HIP 12099 1b for G5 encoded materials, and the crashed Anaconda sites mentioned above for G4 raw materials. If you want to go after materials directly, these are the provided locations.
Materials rewards for missions were also dramatically increased.
Wow - grinders really don't like having fun do they
Collecting mats has been made super easy - just do missions taking the material reward
If you like running around shooting things and whatnot for NPCs and factions, that is a good solution. If that seems like a grind, the position could be reversed