Height definitely matters, but most guys are at a stature where it doesn't significantly affect their dating options, so they're not really impacted by height discrimination in the dating world.
Below are several examples of how a man's height might affect his dating prospects, and this is based on the western world and assuming the average man is around 5 ft 10.
6 ft to 6 ft 4
You are the ideal male height and should not experience any discrimination or disadvantages in dating when it comes to your height. In fact, you will probably receive an advantage for being this tall, since many women are romantically and sexually attracted to tall men. 95% of women are shorter than you in this range.
5 ft 11 to 5 ft 8
You are the average height for a man. Although there are women with 6 ft tall height requirements, these women are the minority and you shouldn't experience much discrimination for your height if you fall in this range. You are still 4-7 inches taller than the average woman, and most women wont reject you for your height.
5 ft 7 and 5 ft 6
You are a little below average height for a man. You should experience some discrimination for your height at this range. But if your looks, your physique, and your social skills are on point, this discrimination can relatively easily be overcome and you can still be successful with women. You are still taller than the average woman and many women in the 5 ft 4 or under range will still be willing to go out with you.
5 ft 5 to 5 ft 4
At this height, you will definitely experience dating discrimination for your stature. At this range, at least 50% of women are taller than you, and many of these women will automatically write your off because you are shorter than they are. However, this can still be overcome if your looks, physique, and social skills are on point, although you may not have as many dating options compared to a man who's 5 ft 10.
5 ft 3 to 5 ft 1
You will experience significant discrimination from women because of your height. Not only are you short, but you're shorter than 75% to 90% of women in your area, and many of these women will NOT go out with you because you're shorter, sometimes significantly shorter than they are. Your dating options are automatically limited, sometimes even significantly limited, if you fall in this range. You will probably never be a Don Juan or a ladies man but getting a girlfriend can still be possible, although with a lot more effort compared to a man who's 5 ft 10. At this height, looking for love in another country where the average woman is shorter such as countries in south america or south-east asia, might be a viable option for you.