Office 2024 does exist as a one-time purchase. It includes classic Office apps installed on one PC or Mac.
For consumer editions:
- Office Home 2024 includes Word, Excel, PowerPoint, and OneNote.
- Office Home & Business 2024 includes Word, Excel, PowerPoint, OneNote, and Outlook.
Microsoft 365 is different:
- It is a subscription.
- It includes the latest app versions, ongoing feature updates, cloud services, and additional security and collaboration features.
- If Microsoft 365 is already owned, there is no need to buy Office 2024, because Microsoft 365 already includes those features and more.
Office 2024 is not a beta product. It is a released, perpetual-license product. It keeps working as a one-time purchase on the licensed device, but it does not get new feature updates or major version upgrades. It receives security updates and fixes during the supported period.
If prompts to buy Microsoft 365 keep appearing, that is because Microsoft 365 and Office 2024 are separate products, and Microsoft promotes the subscription as the recommended upgrade path. The installer branding can also appear as Microsoft 365 even when the license is for Office 2024, because the products use the same installer.