Well for starters, Airtable doesn’t make spreadsheets like Excel/Google Sheets do, it makes databases. Airtable had a webinar that walks through the fundamental differences between the two:
In general, the key difference is that every column/field has a data type assigned to it and every row represents a unique element where the order of rows is meaningless. In a spreadsheet you can say “get the value of the cell below and to the right of this one,” in a database like Airtable you cannot. If you do in fact need a spreadsheet, Airtable might not be worth the cost to you at all because that’s not what Airtable makes. If whatever it is you’re building is well-suited for a database, then the price may be worth it depending on how critical the “pro” features are to you. Airtable does have a free version.
The main draw of Pro accounts is the availability of Blocks (which let you produce PDF reports, charts, maps, etc.) and support for larger tables. Whether or not it is worth the cost of a paid account will depend on how many people will need editing privileges for your databases (Airtable charges by user) and how much you need the functionality provided by Blocks.
Some might say that Airtable is actually cheaper if you factor in the true cost of using Microsoft tools. It’s a challenge to fully measure costs because the cost of not having a fully-SaaS-based solution (without paying for other Microsoft services) is difficult to gauge. What’s the cost of extra effort to make your Excel documents visually appealing and easier to use for non-technical users?
These are rhetorical questions, of course. But there are many advantages to both products; you simply need to assess the advantages of each and come to some degree of quantitative measure in addition to the technical viability of each for your own requirements.
This is not an easy journey, but this community is saturated with messages from customers who are not bashful about the benefits and key advantages made possible solely from Airtable’s unique and desirable UI.