Evolution theory is pretty strong, there have been plenty of intermediates found, its just some people want all the intermediates between A and X rather than just C, G, K, J and T, but fossils require fairly special conditions to form so we may never have every link.
Then broadly there seem to be a couple of types of objectors - those that dislike it on religious grounds, as their sacred texts say their Deity made everything, and reject 'new' information without critically evaluating it, especially if it contradicts their current position.
Those that don't understand the scientific process and think "theory" means "guess", it doesn't. Theories are essentially working understandings and equations that describe the universe that you can make predictions with, therefore they are more useful than laws.
Gravity is a theory, have you ever floated off into space?
Heliocentrism is a theory (the theory that the sun is at the centre of the solar system)
Archimedes buoyancy theory, have you ever just accidentally sank in a seaworthy vessel?
Combustion theory, does your car work?
Quantum theory, are you reading this on a working computer?
The theory of general relativity, have you ever used GPS amd its worked?
We live in a technologically advanced time, where the vast majority of things we interact with are goverened by a well understood theory (at least well understood by scientists).
So if scientists talk about the theory of evolution, they aren't talking about a guess they have about what might be happening. They've already started from the position organisms are created and never change as their null hypothesis and ruled it out. So countless people have worked and refined the theory of evolution. The word theory means its our working understanding and you can make testable predictions, and if more info comes to light the theory can be refined. Because. That's. How. Science. Works.
Of note there have been plenty of examples of evolution in scientific papers, for example E. Coli and citric acid IIRC, though arguably any form of antibiotic resistance to man made antibiotics is evolution, since man made antibiotics didn't exist when bacteria were created.
There are some other things, but this post is already too long