Not quite. Originally, the tighter length limits were intended to give trucks a disadvantage compared to freight trains. But engine technology caught up and more efficient smaller engines negated that limitation.

Not really. A regular truck & trailer is way too big to fit in space-constrained city centers. When it gets really tight they'll just send a box truck, often with a trailer they can leave behind outside the city center for some extra capacity when it's a multi-stop trip [0]. The fancy ones even have doors in the front of the trailer, making it quite easy to move freight from the trailer into the box truck itself.

On the other hand, the highway infrastructure has plenty of space for large trucks. If the roads to & from the main highway network can handle it, some countries will give you permits for all sorts of fancy combinations[1] up to 83 ft long. Considering that it'll still be pulled with a regular cab-over truck, that's a lot of space for freight. They are now even trialing the "Super EcoCombi", which is essentially two full semi-trailers[2], for a total of 105 ft!

[0]: https://assets-global.website-files.com/6424195493a93d7e7fe4...

[1]: https://nl.wikipedia.org/wiki/Langere_en_Zwaardere_Vrachtaut...

[2]: https://i0.wp.com/www.curbsideclassic.com/wp-content/uploads...