No.
That is the whole answer, and the rest of this is about which one to pick and what to do with the others.
Why is being everywhere a bad idea?
Because attention is the constraint, not the number of accounts.
A business with five active accounts is usually a business with five neglected accounts. The same three posts get pushed to all of them, cropped wrong on at least two, with captions written for a platform that is not the one they are sitting on.
That does less than one account posted properly, and it costs five times the effort. Worse, a prospect who finds one of the neglected ones sees a business that last posted in February.
One account, done well, beats five done thinly, every time.
How do I decide which one?
Two questions, in this order.
Where are your buyers already? Not where most people are, where yours are. A company selling to procurement managers and a company selling wedding photography are looking at different platforms, and the second question does not matter if you get this one wrong.
What can you actually make every week? If you hate being on camera, choosing a video platform is a decision to fail slowly. If you can talk easily and write badly, choose the one that rewards talking. If you have a visual trade, photographs are already a by-product of the work.
The right platform is the intersection. Where your buyers are, and what you can sustain. Most people pick on the first and get defeated by the second.
What if my buyers are in more than one place?
Pick the one where you can do the most, and let the second one be a mirror.
There is a real difference between an account you run and an account that exists. The one you run gets original posts, replies to comments, and attention. The mirror gets the same content, reformatted, posted when convenient, with no expectation of conversation.
That is an honest arrangement and it works. What does not work is treating three accounts as if they are all the one you run.
What do I do with the accounts I am not using?
Do not delete them. Park them properly.
Deleting frees the handle for somebody else, and handles matching your business name are worth holding even if you never post. Someone else taking yours is a problem you cannot easily fix later.
Parking means: correct name, correct logo, a bio that says what you do, a link to your website, and correct contact details. Then leave it.
An account with eleven posts from two years ago, but an accurate bio and a working link, reads as a business that chose not to use this platform. An account with the wrong logo, an old phone number and a dead link reads as a business that has stopped operating.
That distinction costs you twenty minutes per account, once.
Should I at least post occasionally on the others?
Only if you can do it without it becoming a chore that damages the main one.
Occasional posting has one genuine benefit: the profile does not carry an obviously stale date at the top. A quarterly post is enough for that, and a quarterly post is a calendar reminder rather than a commitment.
What I would avoid is scheduling the same thing everywhere automatically. The crops are wrong, the hashtags are wrong for the platform, and links behave differently on each. It looks automated, because it is, and it undoes the point of being there.
Does this change as the business grows?
Yes, and the order matters.
Add a second platform when the first is genuinely working and genuinely easy. Working means it produces conversations, not just numbers. Easy means it happens without you thinking about it.
Adding the second before the first is stable is the most common way businesses end up with five neglected accounts. Each was added with good intentions while the previous one was still fragile.
What would I do if I were starting today?
One platform. One that suits how you naturally communicate. Two posts a week.
Every other handle registered, filled in correctly, and left alone.
Come back in six months and see whether the one you chose is producing conversations. If it is, consider a second. If it is not, the answer is almost never a different platform. It is usually what you are posting.
We would rather set up one account you will keep going than five that look active for a month. Tell us what you are working on.
