If evolution is true, why have not scientists been able to discover any "transition form" or "transition fossils" that represent intermediates between species?

It was true that in a moment they needed to discover more transitions, but that was in 1900! and even so evolution had already been confirmed!

Now we have a range of transitions of all species in different stages; for example of the hominid branch (we) we have a lot.

Waiting for more intermediate steps to believe in the evolution would be like having to see the 30 intermediate frames between each second of video to understand that we are seeing a sequence of an event.

Another way to see the evolution in real time is studying bacteria, viruses and mosquitoes for example, because in a short time (given their short reproductive cycle) they become resistant to antibiotics or poisons.

The dog is an example of artificial selection (instead of natural) that comes from the crosses that man made from the time of the wolf, unless one wants to believe that all the races that we see today were creating god and making appear nothing in the last 10,000 years.

There are also many examples of large modern animals that evolved in the last 20 years. Being exposed to new environments and conditions, their small differences between one and the other were playing a role in their success of surviving and reproducing.