i think Bitcoin is only profitable if done at large scales. you must get expensive mining equipment and of course it consumes a lot of electricity monthly. Also its usually much more cost effective to buy Bitcoins with this money instead of using it to buy mining equipment.
If you can invest a lot of money, then go to mining since it will be needing a good set of computer system to mine large amount than the usual mining rate. In return, you will surely receive a lot of money through it even though you have alloted money in the electricity, equipments and others. But if you want it instant then go buy bitcoin and wait for a price hike where you can get profit, it is dangerous note that.
I agree to that, if you really want to spend a huge amount of money then it is better to build a mining since you can earn passive income and it will also grow as the time goes by while investing will not give you daily profit since you only need to hold it for a very long time and wait for its price to grow.