WordPress robust enough

This is more like an advice question than a problem.
For a while now I’m developing a stock photo site in WordPress and WooCommerce. I am convinced that it is possible to attract a lot of customers to choose from a enormous amount of photos. Talking to some developers in the last weekend they told me that I chose the wrong platform.

According to their opinion WordPress and WooCommerce are not able to “do” shops with more than something about 20k products.

In my case (at least I’m aiming for it) we are aiming for 20,000,000 to 50,000,000 products and a lot of traffic.

I need some honest advice here. Is WordPress/WooCommerce up to this or is it a better approach to switch……. and if so, to what.