The question is similar to someone asking "What is the right motor vehicle for you?"
Some people drive a Kia Soul and others are going to need a full size F350 pickup.
Just like with vehicles, the decision on which of the printing options comes down to what you want to accomplish.
Are you looking to go into a full time, full service operation with large volumes? If so, the only answer is screen printing. Are you looking to do small orders and focus on the business that (most) others don't want to deal with (plus individual online sales)? Then the answer is digital heat press. And, if you're planning to go retail and will have a decent foot traffic, selling one off items in-person, DTG can work great.
All three have pros and cons .... but the pros and cons of each relate pretty much only to the purpose for which you're using them.
SO ......
Decide what you want to do and where you want to take your business and "then" make your decision on what process you want to pursue.
(Personally, I made the decision to focus on short runs, usually between 1 and 24 (that the screen printers don't want to screw with) and online sales through Etsy......and do it all out of backroom at the house on a part time basis. For that, the "only" answer is digital and it's worked great for me. I'm operating at a 30% net profit margin, have had tons of repeat business and a growth rate of nearly 30% per year (without any marketing whatsoever) from word-of-mouth. Had zero interest in pursuing Screen Printing - way too much investment and hard work .... and DTG is a PITA if you're not going to be using it all the time).