It may be the tables you are at, as each table plays differently (especially early). Some have multiple limpers every hand, often with 5 of 9 players seeing most flops. Other tables are all in fests, until the crazies get knocked out (usually doesn't take long). Then you have a couple high stackers trying to dominate every hand. Some tables have an even mix of tight players vs loose players.
After a while, things level out and something similar to poker gets played. Depending on the rate of blind increase, it can return to a more chaotic jam fest if blinds start to kill of the lower chip stacks.
This variety is one of the challenges of large MTTs. You have to change your game to combat the people at your table, their aggression, and their stack sizes to blinds. Just when you start to feel comfortable, you get moved to another table.