do thy have a open-ended airline ticket that has no expiration Date on it where u can use it whenever you want? & i know there a travel ban.?

There is no travel ban. You have to check on the individual country's current status. For example, many European countries are opening up to travel within Europe, but they still don't want Americans because we have not controlled the virus.

Now- airlines need to know how many people are going to be on a particular plane, so there are no open-ended tickets. And it's a bad idea to book a one way flight. Many airlines won't let you on the plane if you don't have a return ticket because they know that immigration in the other country won't let you in. Most countries don't want people who might overstay their visas. 

No, there are no such open-ended tickets.  The closest would be a fully refundable ticket that would allow changes, but you'd still have to pay any difference in price for new dates.

You cannot buy only a one-way ticket from the US to the Philippines because you must have a return or onward ticket in order to enter the country. 

There is no blanket travel ban. People are still flying.  There are, however, restrictions on international travel that vary by country.

I don't think such a thing exists anymore.  You could just buy a fully refundable/changeable ticket on a specific date, and then change it.  You would still be responsible for any price difference.

No.  Tickets have to be booked for a certain date for both security and business reasons.  As you said, it would be foolish to buy a ticket with no immediate intention of using it due to the fact the airline could go out of business or no longer serve that route.  Also, since airfares fluctuate all the time, it doesn't serve the airline any good knowing there's x amount of tickets out there just waiting to be used whenever.  They price their seats based on how many seats are left.  

The only real option is to either buy a full fare ticket which would be fully refundable or buy gift certificates but in both cases, tickets will expire usually within 1 year of purchases.