We might be envisioning very different types of websites then. Some random dude's blog - no you don't need to enter your email address.
Buying something online or subscribing to a service? The company does need a way to contact you... which is going to be email.
Email addresses are more-or-less globally unique, which makes them very handy for identifying an individual customer. Verifying the email address is an extra step that can provide the business with more confidence when dealing with a new potential customer. Certain types of fraud vanish or are greatly impeded with email verification, such as carding attacks. Customer support tasks can be performed more reliably and with identity confidence of who they are dealing with, stopping account impersonation attacks and more.
With all that said, sites that choose not to verify email addresses put a greater burden onto the customer for support needs. Password resets, order tracking, cancelling subscriptions etc. all become more difficult if the email address entered by the customer had a type-o for example, or belongs to someone else.
That doesn't mean all sites should verify email addresses - but it does mean railing against any site that does is misguided.
Twitter or discord, why do these require me to confirm an email or phone number when reddit doesn't? Why do shop websites like Etsy require me to confirm my email address before I even decide to purchase or sell anything? If you're worried about credit card fraud, confirm my identity when I give you my payment info, not when I'm merely registering an account.
What you propose would lead to increased cart abandonment. No business wants that.
Account registration is the perfect time to do email verification, if the business is going to do it. The user already is in that "mindset"... and clicking a link is really not very difficult. Everyone in that flow understands what is going on.
Sites like Etsy probably have a significant fraud problem... and as previously discussed verifying email addresses goes a very long way towards minimizing risk.
Companies like Twitter and Discord likely require verification for the same reasons - fraud/abuse. I am aware Twitter has had a history of abusing that data, but the initial reason for verification remains the same.
I'm actually surprised more websites don't require verification. It's easy to do, and the benefits are very obvious. Most users aren't bothered by it either...
Smaller ecommerce sites still keep the Guest Checkout flow available because they would rather not impede checkout for any reason - although that means they take on additional risk. Major ecommerce sites require accounts (think Amazon, Newegg, Etsy, Walmart, Zappos, Chewy) and some do require verification. At their scale, fraud and abuse become very difficult problems that require a lot of time/resources.
OAuth/Social Login has removed some of the need to verify email addresses at the business level. This is because a trusted 3rd party Identity Provider has already done that for you, and most OIDC IDP's already provide an "email_verified" flag of sorts. Depending on your trust level (connecting to Google's IDP vs. random IDP), you can just use this data and assume it's been verified, removing that step for the customer.
Buying something online or subscribing to a service? The company does need a way to contact you... which is going to be email.
Email addresses are more-or-less globally unique, which makes them very handy for identifying an individual customer. Verifying the email address is an extra step that can provide the business with more confidence when dealing with a new potential customer. Certain types of fraud vanish or are greatly impeded with email verification, such as carding attacks. Customer support tasks can be performed more reliably and with identity confidence of who they are dealing with, stopping account impersonation attacks and more.
With all that said, sites that choose not to verify email addresses put a greater burden onto the customer for support needs. Password resets, order tracking, cancelling subscriptions etc. all become more difficult if the email address entered by the customer had a type-o for example, or belongs to someone else.
That doesn't mean all sites should verify email addresses - but it does mean railing against any site that does is misguided.