B1 is where French stops being a subject
B1 is the level where people stop translating in their heads. The Common European Framework calls it the independent user: you cope with most situations that come up while travelling, describe experiences, and give reasons for your opinions without preparing them first.
The vocabulary turns abstract to match. L'entourage, la morosité, l'insertion professionnelle and la solidarité are not objects you can point at. They are the words for talking about society, work and other people, which is precisely what a B1 examiner asks you to do.
The words that make you sound B1
S'expatrier, se reconvertir and se ressourcer are reflexive verbs about changing your own life, and French leans on them constantly. English needs a phrase for each: to move abroad, to change career, to recharge.
La boîte is a good marker of where you are. It literally means the box, and in everyday speech it means the company you work for. Knowing that a word is familier, and knowing when not to use it, is a B1 skill in its own right.
What the DELF B1 actually asks for
The DELF B1 changes shape compared with A2. The writing paper wants around 160 words giving a personal opinion, and the oral has three parts, ending in a debate where you defend a position against the examiner.
That is why the deck leans on abstract nouns and opinion vocabulary. La solidarité, l'intégration, un acte civique and la dépense are the raw material of the subjects the exam keeps picking: living together, consuming, working, belonging.