Quotes from the official website:

Runtime Fee, self-reported

On a monthly basis, you have a choice of the lesser of 2.5% revenue share or the calculated amount based on unique initial engagements. Both your initial engagements and your revenue are self-reported from data you already have available. You will always be billed the lesser amount.

Runtime Fee is forward-looking

The Runtime Fee does not apply to any games created with any currently supported Unity versions. It only applies to games created with or upgraded to the LTS version releasing in 2024 (currently referred to as the 2023 LTS) or later.

Unity Personal: No Runtime Fee, splash screen optional

The Unity Personal plan will remain free and there will be no Runtime Fees for games built with the plan. We will be increasing the annual revenue and funding limit from $100,000 (USD) to $200,000 (USD), and we will remove the requirement to use the Made with Unity splash screen (starting with the LTS version releasing in 2024, currently referred to as the 2023 LTS, or later).

Editor terms

We will make sure that you can stay on the terms applicable for the version of Unity you are using as long as you keep using that version.