We can, and do. They're so far away that even our largest telescopes see only a few pixels.

Examples:

https://en.wikipedia.org/wiki/File:HR_8799_Orbiting_Exoplane...

https://en.wikipedia.org/wiki/File:Beta_Pictoris_b_in_Motion...

When Hubble looked at Pluto, it was a low-detail blur ("The Hubble raw images are a few pixels wide"), and that's within our solar system. https://esahubble.org/images/opo1006h/

Remember, the first exoplanet was detected in 1992, and not by imaging; prior to that we didn't even know if they existed at all. JWST's planning started in 1996.

There is a fundamental physics limit at play here: the diffraction limit is linear with the aperture diameter and gives an upper bound on the resolution of a telescope. Having a longer exposure doesn't help - that's for resolving very faint objects (more light collected -> higher signal-to-noise). To resolve a building-sized object on an exoplanet, regardless of its intensity, we'd need a telescope the size of the solar system. There are some proposals to use the gravitational lensing of our sun to create such a telescope, but those projects are decades at least from implementation.

Need a really big mirror, like size of planet to start with.

Another neat idea is to use the Sun as a gravitational lens. But you you would need it put it way past Pluto to get proper focus. So maybe another hundred years to get tech and resources to that point.

https://www.space.com/earth-like-exoplanet-imaging-with-sun

Maybe the link changed, but the 5th link down the page, "July 12, 2022 Release ID: 2022-032", is "Webb Reveals Steamy Atmosphere of Distant Planet in Exquisite Detail ", link is https://webbtelescope.org/contents/news-releases/2022/news-2...

How much details we can see if based on the wavelength of light and the diameter of the telescope. And if you worked it out, the telescope diameter would have to be enormous.

https://calculator.academy/diffraction-limit-calculator/#f1p...

However gravity can bend light so there is some thought of using the sun as a lens. However the observation would have to be pretty far away from our sun so its just wishful thinking in our lifetime.

https://www.freethink.com/space/gravity-telescope

For now the best we will have to see a dot on image via coronagraphy and maybe understand more about the exoplanet through spectroscopy.

It’s because those planets are incredibly far away. The distance is so huge, there is no way to even picture it. It would be a single pixel on any telescope we could conceivably build. What we can do though is measure the chemical composition of their atmospheres. This could be very interesting if we found some hallmarks of life on a rocky planet.

There aren't telescopes big enough to do that.