Data structures – How to get the coordinates of a point from a plot in Mathematica v11?

I've been using mathematica plot points for over 25 years and it does not work at all with version 11 anymore:

gr = plot[Sin[2 [Pi] X], {x, 0, 1}

plot result

gr[[0]]

returns graphics

gr[[1, 1, 1, 3]]

results

{Directing[Opacity[1.], RGBColor[0.368417, 0.506779, 0.709798], AbsoluteThickness[1.6]],
Line[{{2.04082 * 10 ^ -8, 1.28228 * 10 ^ -7}, {0.000306718,
0.00192716}, {0.000613415, 0.00385419}, {0.00122681,
0.0077082}, {0.0024536, 0.0154158}, {0.00490718,
0.0308278}, {0.00981434, 0.0616262}, {0.0196287, 0.123018}, ....

The points seem to be there and accessible, but

gr[[[[[1, 1, 1, 3, 2]

returns "mappingPrivateTag $ 109972 # 1 "instead of line[] with the points!

How to get points in version 11 (and up)?

Thank you for your help.

Denis