You've noticed that the share price drops by the dividend amount on the ex dividend date. Naturally, because a share that's going to guarantee you $5 if you own it tomorrow is less valuable than one where you have to wait for a year to get the $5.

What you don't see is the gentle pressure pushing the share price up as the year goes by, and next year's dividend date gets closer and closer. A share that guarantees you $5 in a six month's time is worth more than a share that guarantees you $5 in a year's time. When the ex dividend date is only 3 months away it's worth even more.

You won't notice that and can't notice that effect for ordinary shares, because there are so many other factors that affect the share price much more strongly. But you will see this exact effect if you look at the price of exchange-traded fixed income instruments: these are tradable on the exchange but give you literally a fixed amount of cash regularly. The price drops on the ex date, then slowly climbs until the next ex date. You earn the same amount per day no matter how many ex dates you cross.