Quick napkin-at-the-restaurant maths:
An iPhone 15 picture taken at 24MP in Jpeg tops up at 5MB size (no 48MP, no Proraw). That means that a 2TB iPhone 15 can hold up to 400k of these. Considering that most won't reach 5MB and that you can use lower-definition formats and resolutions, yes, 500k is largely possible.
And that's considering that all pictures were taken with an iPhone 15. Plenty of people have a library full of pictures taken with much older camera systems and thus much smaller in storage space.
The answer to your question is yes, that's perfectly possible.