Elongated plots in Hungary

I think it predates a lot of the discussion around property development. The old division of land was called a 'Hold' and long and narrow plots allows for easy farming while maintaining access to the road. Long plots mean fewer turns with a plow.

Similarly in Poland and Quebec. My guess would be that Hungarian inheritance laws/customs favoured the division of land between sons rather than the firstborn inheriting the lot (as in a lot of other European countries).

You see a lot of elongated lots in the UK here as well, and this only a guess but I suspect the reason is likely to do simply with the practicalities of property development and land sale.

If you own a plot of land and want to put houses on it, then obviously the way to get the most houses on it would be to divide it into square lots, and build new access roads as necessary so each house has road connection. This also means building out the associated utilities like electricity and water and telecom that run under the road. Doing this is really expensive, and you may not have the means. It may also be legally prohibited to build new road.

So you have this piece of land and for whatever reason you can't build road, what do you do? You subdivide along the existing road that's already there so everyone has access and just enough width for a house. And that's what this looks like.