This thread is dedicated to the 'Say So' soundalikes, which apparently has been a trend to follow in Pop in the last half decade.
From the top of my head, here are the songs that have used 'Say So' as 'inspiration' and also the tracks that I believe are the sonic palette from which it has been created.
After its release:
Espresso by Sabrina Carpenter
Puntería by Shakira & Cardi B
Lottery by Latto & Lu Kala
Let Love Go by Mabel & Lil Tecca
Closer by Saweetie & H.E.R
Weekend by TAEYEON
Kiss Me More by Doja Cat & Sza
Experience by Victoria Monét & Khalid
Before its release:
Lovefool by The Cardigans.
Good Times by Chic.
Any other suggestions?