Life is sales.
Simple as that. At least any sort of professional aspect of your life.
By this, I mean every action that you take in your professional life in some way boils back down to sales. You could be an individual contributor, a manager, a founder or anything in between and everything you do could be reduced to sales. This argument might be slightly reductive but when I sit here and think about it I truly feel that way. I also believe the word sales might not have enough nuance to describe it.
Let's start with the more conventional path: W-2 employment. If you're on a salary you probably got there by going through an application process, some interviews, a contract negotiation etc. Every phase of this process is sales.
Drafting a resume or a cover letter is attempting to convince the person (or Ai these days) that you're worth speaking to. The entire interview process is trying to display your competence to the interviewers. This is the first place where 'perception is reality' can come into play. You could be the perfect candidate for the job and fully capable of completing everything they need you to, but if you don't convey that in the interviews you'll never have the opportunity. On the flip side, you can be completely incompetent and have no idea what you're doing, but if you somehow manage to convince the interviewer that you do then you've achieved 'success' in the application process. A lot of people think that their skills are what get them jobs when in reality the skills are just the supporting evidence in the argument to hire someone. Having or not having skills doesn't even fully cover it because you also need the ability to display those skills such that the other person believes you have them. You need to be able to sell.
You would think the sales would stop there, but no. Most states are at will employment where either party can walk away from the engagement at any time. Given this, you have to continue convincing your employer that they should spend money on you. Everyday you show up for work you need to portray competence, a strong work ethic, and ability to collaborate with others in order to keep getting paid. Whether you realize it or not you are selling all of this. Constantly. The moment you fail to continue selling this is when you'll find yourself without a job.
Beyond W-2 employment we've got the general concept of 'entrepreneurship'. I think this generally takes the two forms of: consulting and product. In either case you can work alone or with others, but I consider the consulting side less interesting to discuss with regards to sales because I think the connection is much more obvious. Even with product based businesses there must be some aspect of sales in order to generate revenue, but it's much more interesting to discuss the less obvious aspects.
Operating in a leadership capacity at a company is also a constant sales motion, largely internal and interpersonal. The direction of the company first needs to be decided upon by the whole leadership team. The members may have differing opinions on what is the current priority at the time. Cue selling your vision of what the focus should be to the other members of the team. After successfully selling the other members of leadership on the correct path, you now have to turn around and sell IC members on that priority as well. Once you've done all of that and begun executing on the plan you now have to sell external stakeholders. Customers need to be told why the effort will be beneficial for them, especially if there are inconvenient changes that need to be made on the way there. Investors are a whole different ball game.
Sales is likely not the right word for it. I think persuasion is more apt, but has an almost malicious connotation to it. As if you're trying to manipulate those around you against their own interests. Swaying people's disposition toward something is simply a fact of life if you ever want to have a proper impact on the world. The alternative is being persuaded and following those with such a skill. I still think my own abilities have yet to be seen.