To help people better understand what this game is, I added the following to the OP:
Exactly what does the gameplay involve?
Combat - You play as a team of four characters, each with elemental abilities. You can switch characters instantly, and only one character from the team is ever on screen at a given time. You fight using various elemental combinations. Each character has basic attacks, and two skills on cooldown timers, one short and one long. There is no lock-on function to target enemies, but there is a dodge function that also doubles as a run button. The main character has a sword, while others can be skilled in archery, magic, spears, etc.
Exploration - This is where Breath of the Wild comparisons are pretty accurate. You can climb most surfaces, you have a stamina bar, you have a glider for air travel, you can swim, you can place pins on your map to mark areas of importance, and the list goes on. There are hundreds of treasure chests to find, some in the open, some that require enemies to be defeated, and some that require light puzzle solving. In most chests you find items that can boost your character's XP. This, not combat, is the primary method of gaining XP.
Genshin Impact is a single player game, not an MMO. Multiplayer is completely optional, and supports up to four players.