Basically, TrueType fonts are not bad or worse than other fonts. But you have to know that TTF is an old format with some enhancements which have been made in the recent years.
Old TTF fonts use a vector matrix of 1'000 x 1'000 dots only, while the enhanced TTF fonts can use a matrix of 32'000 x 32'000. It should be obvious that the new matrix offers much more quality when the curves of a letter or glyph are described.
There are many old TTF fonts with the rough matrix on the road, while Arial and Times New Roman definitely use the enhanced matrix.