Buyer and Math Question

So I saw a business in a tangential industry to my own company is in. The adjusted “EBITDA” for 2019 through 2023 was $233k, $88k, $496k, $1450k, $1,500k. That’s a mean of $753k and a standard deviation of $603k. The business was hollowed out during the pandemic. And they told me they can’t get me numbers from beforeredactedI reluctantly made an offer. They were insulted and said that they have standing offers of $5-$6MM. That’s a 7.3x EBITDA multiple if the price is $5.5MM.

So my question is two fold:
1) If you have a 7.3x EBITDA offer on a business that has a standard deviation as a percentage of EBITDA at 80% in a basic project based non high growth industry why on earth would you not sell that tomorrow?
2) Who would pay that for a corporate vents company?

Looking for perspectives on this.