Angle is a purchase. Seventy-nine dollars buys the pack and the plugin for Sketch, Figma and XD, and it keeps working indefinitely. The catch is stated plainly on its own site: free upgrades for newly released devices run for one year. After that the pack still works, it just stops learning about new phones.
Mockuuups is a subscription, with plugins and a desktop app and a library that keeps growing while you pay. You never own it, and it never falls behind.
That makes the comparison unusually clean, because it is the same trade in both directions. Buying is cheaper if your work does not depend on the newest hardware, and a mockup of last year's phone is fine for most presentations. Subscribing is cheaper than repurchasing if it does, which is mostly true for people presenting apps to clients who will notice. Neither is a better product; they are different bets about how fast this category moves.