While agreeing that your ideal situation may have originally envisioned all as landowners, it is never stated in God’s Word nor has it ever been actually practical in real life.
The double-portion to the firstborn law would have chased most off the land within a few generations. As the land portions became smaller and smaller they would have become too small to sustain most households. The small landowner would have been forced to sell his land to his first-born descendant who could afford to buy up small parcels. That is common sense to me. If my logic is wrong, tell me where.
The small landowner would then have two choices: (1) work for his relative as a day-laborer or (2) move to the city and take up a trade. In either case he would cease paying tithes. The landowner would pay the tithe of food or herds and the products from craftsmen are not a tithe-able item. Jesus and his father are good examples. How many brothers got a share of Joseph’s carpenter shop?
For example a 1000 acre farm with four sons would be divided after one generation into plots of 400-200-200-200 with a double portion to the firstborn.
The second generation split would be 160-80-80-80. The third generation split would be 64-32-32-32. And the fourth generation split would be 25.6-12.8-12.8-12.8. Like all societies the masses eventually move to the cities. The Early Dark Ages and Dark Ages began around AD700 when the poorest farmers sold their land for protection and became tenant feudal farmers.