Exactly. This is a good answer to a similar question I've read recently.
HTTPS downloads in general provide two things: confidentiality of data
transfer, and integrity of
data transfer.
For purposes of integrity, HTTPS apt repositories provide no benefit. Apt
release files are already PGP signed by the distribution, so any files forged
in transit would be identified and rejected regardless of HTTP or HTTPS.
Without HTTPS, third parties like your ISP can observe which packages you
download, however, that has generally been considered to be of little
consequence.
