What are the main obstacles that prevent the majority of adult players to make progress at chess and reach their goals?

Lack of Motivation:

Lack of motivation, is the biggest progress stopper at chess and life alike. Many adult players are simply not motivated enough to get better at chess.

Often known as a game for the intellectually gifted, chess is the best sport to exercise the most important organ in our bodies: the brain. While Chess Grandmaster Bobby Fischer made it popular in the 1950s and 1960s, the game is still widely played around the world today among participants of all ages, from the young to the elderly