The one thing about comparing players of different eras you can say is that the stars of yesterday would star today, and vice versa. If a guy was 10% better than league average in 1950, he would be that in 2020.
The greatest of the great would be great no matter what the era. There are a few examples that show that. Ted Williams was great in the late 1930s, and was great in the late 1950s. Stan was great in the ‘40s, and still had enough to pull the ball for a single in his very last at bat against the hard-throwing Jim Maloney in 1963.
The game has changed. Williams and Musial would strike out more today, but they would be the Mike Trout’s of baseball today if we could warp time in some manner and have them born some 60-70 years later. Likewise Trout would be the Babe Ruth/Jimmie Foxx of the ‘20s and ‘30s.
Although you cannot truly find a comparable Babe. He may never be duplicated – he started out as a Randy Johnson/Steve Carlton type and transformed into a Barry Bonds.