Why there's a narrative among PS5 community that gaming discs are cheaper?

Hi everyone. I recently bought my first PS. It was a childhood dream and ever since I got my job I was saving for this.

When I was researching about buying PS5 in most of the online communities they were recommending to spend extra and take the disc version because complete digital gaming is expensive.

I went ahead and bought the disc version but now when I'm comparing prices of games during sales in PS store and pre-owned discs in websites like gameloot, game nation and console garage there's not much difference and sometimes it's cheaper in PS store.

Is there any other website I should be looking into, because it's starting to feel like there's not much financial benefits like I expected?