With more people applying for even fewer jobs, roles are being filled faster than ever. Which makes it that much more important to customize your resumes and cover letters.
Yes, you should customize. Not necessarily from scratch each time, but you need to tailor. Swap in relevant keywords. Reorder your experience. Adjust your summary to align with the role.
Create a master resume with all your accomplishments. Then pull from it for each application. This makes customization faster without sacrificing quality.
The extra 15–20 minutes per application can be the difference between an interview and silence.