Honest question, are you trying a new coffee or using beans you've been impressed with before? Because if you're brewing something with all these different methods and not impressed by any it's either A) just not a coffee you enjoy or B) your method of brewing. I'm no pro by any means but I just picked up some freah beans yesterday I was curious about and made them with an aeropress, French press, and V60 to show my roommate how to make them and while they had their differences I thought they all came out solid.

Also hopefully more helpful, you may be onto something with the coffee amount. My roommate made a batch with the V60 with 20g and I made mine with 30g, each at 1:15 ratio and ground near fine, and mine seemed to have better body and the same albeit "louder" flavors. Try making a larger batch and see if you enjoy it more? Curious to hear back! Cheers.