go to one of these portfolio manager websites that has price history of altcoins then do the following:

choose 1 or 2 years ago as your start (start at 2017 or 2016) then
1. go all in bitcoin with your $2000
2. choose multiple altcoins and go in those with your $2000

now compare your results. i'll tell you what bitcoin investment result could have been: if you had invested $2000 in bitcoin in 2016, now you could have had $44000 with current price not the ATH. can you claim the same with bag holding altcoins for 2 years?