There is a lot of modern art out there but no matter where you go looking for modern art you will probably be thinking that most modern art looks the same!
Well, you are correct! Most modern art does look the same and will continue to. You will find that the general style of modern art will look the same for a while and then a few months later will totally change. What you will also find is that when the general style of modern art does eventually change, every other artist will paint the same. This is modern art/contemporary art fashion!
Modern art/contemporary art goes through fashions just like clothes do and if you are a follower of clothes fashion then you would have probably experienced buying clothes that look great at the time of buying but a while later you think, 'why did I buy that?'. The same can happen with modern art/contemporary art. You can easily get caught up with the general style of modern art that is fashionable at the time of buying and then a couple of months later think, 'why did I buy that?'
Making a mistake in the piece of modern art that you choose to buy has a much higher cost than making a mistake with an item of clothing. For a start there is the cost of buying the piece of modern art/contemporary art which can be expensive. Then secondly (which people forget) is that you have to live with the item of modern art!
The problem with modern art/contemporary art going through fashions is that it's almost like peer pressure. If every online gallery is selling similar styles then subconsciously you will start to temporarily like the modern art because it will seem the norm at the time. Don't get sucked in!
Buy modern art/contemporary art that you like. Although most galleries will sell similar modern art that is in fashion, not all do! So if you like abstract art and it isn't in fashion then buy abstract art. If you like abstract expressionist art then buy abstract expressionist art! Don't get caught in the modern art/contemporary art fashion trap!