Too much engine oil can be a cause of too much or too high of oil pressure but having high oil pressure is not usually caused by too much oil.
Instead too high oil pressure in a cars engine is usually and most commonly caused by a clogged oil filter or a bad oil pressure relief valve.
Your engine oil pressure sensor could also be causing the oil pressure to read too high even when it's not.
Either way too much engine oil is not good as it can cause damage to your engine and could cause the engine to seize up due to a lack of lubrication.
When the engine has too much oil it can create foam in the oil which makes the engine oil pump not work properly to suck the engine oil up out of the engine pan and send it through the crankshaft and engine.
So you would get a lack of engine lubrication which is not good for your engine.
Overfilling the engine by just a little bit is not harmful but overfilling the engine by a quart of oil is harmful and if you overfill the engine oil you need to remove the drain plug and drain the excess engine oil out of the engine.