Just using one email account is quite common, but from a security point of view it has disadvantages. Ideally, it is better to have different email accounts for different purposes.
If a phishing email claiming to be from your bank comes to the account you use only for social media, you know it’s fake.
Spam
Code can be injected into a shopping cart and goods purchased online using the target’s account. To hide this activity, the victim’s inbox is flooded with spam to hide the illegal transactions.
Spam can be more than a nuisance; it can be malicious: Malspam
Email should never be considered private unless it is encrypted. You can use Tuta Mail or Proton Mail to send encrypted email. Even if the recipient does not have either of those programs installed, they will receive a link for an encrypted message. You can create free accounts with both of these email clients.
I used to use Proton solely for encrypted email, but, I find Tuta more practical for both encrypted and unencrypted email.
You do not have to spend money to increase your privacy and security, you just need to make some changes.
Ronnie's Blog 