I was thinking of a good and healthy way for both users and company to support long term users.

I got to this idea.

Every year a customer has a subscription they get 1% more lifetime discount. (Until the subscription is cancelled)
So after 1 year you get 1%
2 years 2%
That goes up to a maximum for example 25% after being a loyal customer for 25 years.
Or 50% after 50 years that's up to the company what they feel good about.

If you cancel your subscription once (or can't pay it) you lose all the build up discount earned and you need to start over.
Upgrading plans to for example a family plan or downgrading a plan should be possible without losing the discount.
If you downgrade to a completely free account you lose the discount.
This way long term users will want to keep their earned discount by continuing the subscription. But they will also feel happy they are not forgotten and actually receive a cheaper price then newer users.

The company ensures that they have paying users over the long term and the users have a very good discount the longer they stay.

I'm also specifically talking about a discount because the company can still raise the base price of the subscriptions if they want or need to.

Lastly I the company can still promote their products with a black Friday price giving them 50% or maybe the maximum discount earned after being loyal for x amount of years. But they will only get that price the first year and each account can only use that promotion once.
That way they would need to make a new account and email every year if they want to keep getting the black Friday promo for example. (I think this happens now also from time to time)

What do you guys think about this?