BHD every area is different I am sure. Your experience tells you that it is critical. But that is based solely on your experience. Others base their opinions on their experiences.
I have a kid in the Majors that never played travel baseball. He played local rec league and then HS. He was drafted out of HS and reached the Majors. I have another that did not play travel he only played local rec ball. He was also drafted and has done very well and I expect one day to see him in the majors. I have had guys that played travel ball that have done very well also.
I have had several come into hs very well schooled in the fundementals of the game and advanced for their age. But their talent only took them as far as solid hs players. I have had guys come in very raw in their baseball skills but developed into outstanding baseball players and played at a high level after hs.
The most important years are the HS years when kids begin to develop physically and mentally. This is where the instruction , coaching , desire , work ethic come into play. Everything prior to these years is all well and good. But in the end the kids with the ability are going to win out , period.
That is my experience. Yours tells you something different. That means your right in your experience. My experiences tell me something totally different.