Search systems aren't real people or real businesses either. Never mind details like how you define and enforce "real" in a decentralized way across N legal systems with wildly varying ideas of what it means to be a "legitimate" business. There is no system or ledger you can query to find out if a given person is real or a business is legitimate. This is exceptionally unlikely to change on a useful timescale.
The basic problem with email is that it assumed good-faith participation from the parties involved. It was assumed that only legitimate actors would have the resources to participate and they would always be well-behaved. This, it turns out, was flawed on several counts. For one, it assumed legitimacy could be assured. For another, it assumed legitimate users would be well-behaved and would never abuse services for gain. For a third, it assumed account takeovers or other impersonation attacks wouldn't happen.
Every de-centralized system that aspires to not have email's problems needs to take them seriously.
The basic problem with email is that it assumed good-faith participation from the parties involved. It was assumed that only legitimate actors would have the resources to participate and they would always be well-behaved. This, it turns out, was flawed on several counts. For one, it assumed legitimacy could be assured. For another, it assumed legitimate users would be well-behaved and would never abuse services for gain. For a third, it assumed account takeovers or other impersonation attacks wouldn't happen.
Every de-centralized system that aspires to not have email's problems needs to take them seriously.