Ask most business owners what their shares actually do, and you'll get a confident answer that's usually wrong.
They'll tell you shares represent ownership. Fair enough, they do. But ownership of what, exactly? The right to vote? The right to a dividend? The right to a slice of the company if it's sold? Most people assume all three come bundled together as one package, because for years that's exactly how their shares have worked. One class, one set of rights, everyone treated the same. It never occurs to them that this is a choice, not a rule.
It becomes a problem the moment the people behind the business stop being identical. A couple run a company together, but only one of them has used up their personal allowance. A founder wants to bring in a brilliant operations hire and give them a genuine stake, without handing over a vote on company strategy. Two directors want the freedom to draw dividends on their own schedule, in their own amounts, without checking what the other one is doing. I see this constantly, and in every case the business owner is trying to solve a problem that one class of ordinary shares simply cannot solve. Not because they've structured something wrong, but because ordinary shares were never built to flex.
This is what alphabet shares are for. Instead of one class of shares doing everything, you create several, often labelled A, B, C and onward, and you let each one carry different rights. Different dividend entitlements. Different voting power. Different claims on capital if the company is sold. The letters mean nothing on their own. What matters is that you've stopped treating "ownership" as one indivisible thing and started treating it as several things you can hand out separately, to the right people, on the right terms.