All tablets are going to look dim compared to the 740.
The 740 has a brightness of 1000+ nits (original 740 = 1300 nits; 740b = 1100 nits). Tablets will max out in the ~600ish range, and most are much less than that. Not sure which Samsung tablet you have, but the circa-2015 Tab S2 has a 330 nit display. (For what it's worth, this is what I fly with and find it suitable except for when the sun is shining right on it.)
Flying with a dark-colored shirt can help reduce glare, and some folks have fashioned table hoods out of lightweight materials to shade their screens.