Desktop. Seriously unless you absolutely have to have the portability, a desktop is a better choice. Its upgradable, quieter, runs cooler and will almost always be more powerful at any given price point.
Otherwise at 700 bucks youll probably have to look at an Acer or maybe a MSI if they are on sale. Another place that might be worth checking would be the used market, you could probably get a 3 or 4 year old laptop that has a RTX 20** in it.