Digitally which defeats the purpose. Others particularly Jazz and Classical
Still use tape. Most remastered from the 60s and 70s indicate if they were made from the original tapes.
I am sure the quality varies on repressing which is why getting original albums are popular. But if it is repressed on 180 or 200 gram vinyl they tend yo be better. The main problem with 40-50 year old vinyl is the dirt and scratches but there are great cleaners that work wonders.