Bhutan is small, and made of mountains. The population is about 800,000, which you could fit in a few square km of Mumbai (!). The country is not very large, but the vast majority is rural and undeveloped. It's slow to drive around -- roads are mountainous and twisty -- but we got to see the larger towns, a lot of monasteries, and some of the rural areas.
If you do some research on Bhutan, it's usually described as being hard to get to, or hard to get permission to visit. The number of tourists is indeed limited, and you do need permission to come. However, it's relatively easy to get the permission: you just arrange for a tour with an official guide, and pay for it. The government heavily regulates tourism. You are not allowed to come into the country, or travel anywhere, without a guide. The only exceptions are for citizens of India, Bangladesh, and Mauritius (!) -- these visitors can roam freely, without paying a daily fee, or needing a guide, so lots of Indians come for short trips, especially from Kolkata. (India is about 40% of the visitors, and the US is second after that.)
Otherwise, every visitor is charged the same minimum daily rate, around $200/person/day. That includes everything: all meals, all hotels, a car, a driver, a guide, visas, and so on. Although we stayed in 'tourist hotels,' we had quite a bit of flexibility as far as where we ended up eating or what we saw. Kids are free or half-price, so overall it was only slightly more expensive than some fully supported trips we've done around India.
The company we went with is Heavenly Bhutan. They have a couple dozen guides, and were super helpful. In particular, we made quite a few changes to our itinerary along the way, and it was always easy to do so. There are a few dozen guide companies, and several hundred official guides.
Last modified 09 Jan 2021