No, Studio doesn't compete with streaming. It isn't EVEN or streaming, it's EVEN and streaming.
Artist exclusive, not platform exclusive
A Studio release doesn't pull the album off streaming or delay the wide release. Fans who buy on the artist's site get early access to selected tracks, and the full album goes wide on streaming on release day exactly as planned. No one cancels Netflix when they go to the movies.
What the early window actually is
The early window is a window, not a wall. How much comes early, a few tracks or more, is set per campaign within the chart rules, and everything unlocks automatically at street date. Early access is the reward for buying rather than a penalty for streaming.
Why it tends to help the streaming release
The fans who buy early are the ones who show up on day one everywhere else. A Studio campaign concentrates that audience, gives them something to do with their enthusiasm before street date, and hands your team their contact details, so the wide release launches into a warmed-up base rather than a cold one.
EVEN is not a distributor
EVEN doesn't upload to streaming platforms, so your distributor relationship is unchanged. Releasing on EVEN doesn't stop you going wide, and it isn't a substitute for distribution.