Beyond all reason is an RTS and team matches are very popular the most popular being 8v8. Now there is a mechanic where you can share resources(energy/metal/buildpower) to a teammate anywhere on the map instantly for no cost. You can also share units. This leads to a lot of co op strategies where two or more players pool resources to build a higher tech lab faster and then use those higher tech units to run the tier 1 units over. This is fun to watch in pro play but in casual and everyday ranked play its a problem because you are forced to co op yourself or die. You cant scout the co op fast enough to react so you have to co op/share/boost a player or risk them dying to a co op rush.
There is has been a huge debate raging in the discord thats 50k+ messages long on if the mechanic is to powerful and something should be done. Slowly i think all the higher OS players have come to agree that its way to broken but there are still a lot of players saying its completely fine and its a skill issue if you lose to it.