All products must come to an end. That's just a fact.
If you think about it, products are just a way for investors to make money. Investors give funnel money into products through companies. The products then generate revenue at a rate much higher than other 'safer' options. Resulting in the value of the company going up. Which ultimately results in value for the investor in terms of equity.
But it's impossible for products to keep growing at a fast pace. They cannot keep growing at say, 25% yoy for eternity. This is because there will come a point where there literally won't be enough money left in the world.
That's why when companies sense that a product is reaching that glass ceiling, they stop investing in it and use the funds to create new products. And this cycle keeps going on and on.
For a company to be successful in the long term, it would need to have to keep doing this across generations.
So, what does this cycle look like?
Initially, the product is just introduced. This is sort of a discovery phase where only the enthusiasts try it out. The goal here is to get initial feedback and start refining the product into something which solves pain points for the potential users. All efforts are concentrated in the direction of understanding the market better.
Then once the product is in a shape where the company has seen enough positive feedback to believe in the success of the product, the growth phase starts. This is the phase when the company pours money into marketing and sales and feature development. At this point the idea is already validated and the focus is on acquiring new customers. This phase keeps running till most of the addressable market is a customer.
Now the product enters the maturity phase. This is when the product is generating a good amount of revenue and has a loyal customer base. But acquiring new customers is very expensive and doesn't make economic sense. At this stage, the company slows down the money they are putting into the product and directs its funds to new products.
Slowly with time, the user behavior changes or new products come to the market or some new technological advancement happens in the world. At this point, the customer base starts declining and the product is declining.