Webb's physical dimensions are larger than Hubble's. The "collecting area" of Web is 273 sq ft to Hubble's 46, per Wikipedia. The two telescopes are sensitive t

Webb's physical dimensions are larger than Hubble's. The "collecting area" of Web is 273 sq ft to Hubble's 46, per Wikipedia. The two telescopes are sensitive to different (but somewhat overlapping) bands of light. Hubble worked through the visible spectrum while JWST is almost exclusively infrared. To the "can Hubble do anything Webb can do but with more time", the answer is no, due to the lack of mid-infrared sensitivity, among other things like atmosphere.