It only matters if you care about tearing. Which competitive gamers don't.
Gaming but with no tearing is wonderful. Can't believe I tolerated it's awfulness for so long. 100 Hz to 144 Hz is damn nice. If you have no FreeSyn or G-SYNC on a 144 Hz screen, either you drop settings low to guarantee to stay over 144 FPS, or you choose to be at 72 Hz (maybe 36 Hz), or you choose tearing. Both of these suck. The upgrades to almost any rig that you would need, to guarantee staying over 144 FPS at settings that look nice, cost much more than the cost delta of FreeSync on a monitor.
Having 144hz with no freesync is madness. Unless your game sits at 144fps constantly you will get screen tearing. There's loads of examples online about it, Freesync will stop tearing all the way down to about 40fps.
In what way?