Technically, you could just sit really close to the screen, but it's a bit more complicated than that.

For one, the screen you're sitting in front of would have to be massive. A 55" or even 65" screen is unlikely to cut it to get an IMAX-like effect with 1.43:1 content. You have to remember that a good chunk of the left and right sides of the screen are going to be chopped off through pillarboxing when watching IMAX-formatted shots. Mixing in the rest of the movie that isn't in this aspect ratio will be especially jarring; either you switch to letterboxing for the 2.39:1 shots (to the point that the shots that are meant to be smaller actually end up larger) or use a tiny center portion of the screen. Either way, the transitions between these aspect ratios will be way more jarring than on a screen properly fitted for it. Screens in IMAX theaters are large enough that switching between these two wildly different aspect ratios in the middle of a movie doesn't ruin the more traditional widescreen scenes.

You also have to keep in mind that the screen at the IMAX theater isn't perfectly flat. The outer edges on all four sides are curved in a bit to try to keep the distance from your eyes to any point on the screen consistent, to the extent that would be possible in a theater with a wide seating area.

All of this isn't to say you can't have a comparably immersive experience watching movies on your TV by sitting really close to the screen. You just need content that's properly sized for that display. A niche, non-standard format like 1.43:1 IMAX is always going to look best in a purpose-built venue that fits the format. You get the best "big screen effect" by just using as much of whatever display you have as possible.

Also remember that most films these days released in IMAX theaters aren't actually in 1.43:1. Most are in 1.9:1 or even 2.39:1, which don't take advantage of the specialty display and will look perfectly normal on your TV, even for any expanded-ratio shots. As far as I'm aware, only two films released this year had any 1.43:1 footage (Lightyear and Nope), and only two others are known to be planned for next year (Oppenheimer and Dune: Part Two).

True IMAX screens are absolutely massive and like almost like a square when you're standing in front of them. These are 50-60 feet (15-18m) tall, sometimes even more.

The vast majority of true IMAX theaters are found in museums as IMAX were exclusively used in short documentaries from the first film released in 1970, all the way until The Dark Knight became the first narrative film to use the camera for part of the movie in 2008. Because of how unwieldy the camera is and the extreme expense of the film stock it uses, no feature film has ever used it for its entire run time, and it's unlikely that one ever will.

There are, however, a few full size IMAX theaters out there outside of museums. The IMAX theater is Sydney will be the largest of these, and in the US, there's one in New York in a few in California. Wikipedia's list of IMAX venues denotes which theaters are formatted to the 1.43:1 aspect ratio.

The thing that makes an IMAX format like this impractical for home release is that some scenes of the movie were fitted to a 1.43:1 aspect ratio, which is the same as IMAX 70mm film and the purpose-built IMAX theaters designed to show that. The upper and lower ends of the image stretch into your peripheral vision when watching this in the IMAX theater (which the cinematographer must take into account when framing the shot), but would be pillarboxed when watching it on any other display, including a consumer TV. If you tried to show the full IMAX-format image on your TV, the effect just wouldn't work.

They could, however, use the more limited 1.9:1 IMAX format for a home release, which is the aspect ratio used in retrofitted IMAX theaters found in most multiplexes, and is much closer to the aspect ratio of your TV.