It is cheap because supply is infinite and there is no mined scarcity premium. Natural diamonds are artificially kept expensive by De Beers-style supply control. Moissanite is a manufactured crystal produced in bulk. The 'catch' is not quality, it is simply that there is no prestige premium attached.
Short answer: yes, for most people it is a great choice.
I went with a 2ct equivalent moissanite for my engagement ring and I have zero regrets. For 800 dollars I got a stone that looks huge. In sunlight it honestly out-sparkles my coworker's 8k diamond.
The main tradeoff: moissanite has no resale market and some diamond purists will side-eye it. If you are buying for sparkle and size on a budget, it is unbeatable.
A 1ct moissanite looks slightly LARGER than a 1ct diamond because moissanite is less dense. A 6.5mm 1ct diamond is about the same visual size as a 6.5-7mm moissanite. In practice the difference is tiny but moissanite wins slightly on face-up size.
I disagree a little. Moissanite is beautiful but it has a very specific, almost rainbow flash that some people find unnatural. Try seeing one in person in daylight before you commit. In dim indoor lighting it can look grayish compared to a nice diamond.