That's very true. It's less that it can happen, and more that it's happening with virtually every trade agreement at once, along with dozens of diplomatic norms.
That said, the authority of the executive is undeniably stronger today than back then. Congress has acquiesed its authority and powers on virtually every issue imaginable and it alternates between being too complicit and too incompetent to change that (and too gridlocked to achieve meaningful policy anyway).
There are too many metastisizing issues to count at this point.
Congress is hopelessly broken, gridlocked and unable to pass policy on its own merit. That's how we end up with quadrillion page omnibus bills every year. It's a failed institution, and it's been this way since at least Reagan.