Actually our experience is entirely different. We place our certified
ESL teachers in English schools around the world and know for a fact that a teaching practicum is not an essential requirement for many positions.
Of course, it depends on where you want to teach and at what level. CELTA has a high profile in Europe and is undoubtedly a popular qualification that will open many doors however it is also true that in most places around the world the basic requirements for entry level teaching positions are a degree plus a TESL/TEFL certificate - not necessarily a CELTA.
As for the amount of hours attached to a certificate the general perception is that the less hours a course is worth the less is the value of the certificate. It’s got to be said though that employers rarely specify how many hrs a TESL/TEFL Certificate should be worth. What matters to them is that you are certified.
Personally I would recommend that more than the number of hrs attached to a certificate you look at the course content. Start by asking a few providers for their course syllabus and compare them. Check their tutors’ credentials. Make sure the course requires some actual work on your part and it is not based on “Yes or No” answers or “Read This Unit and Summarize It” type of coursework. Try and find out what other students who have taken the course say about it. Basically do as much research as you can.
You could start by taking a look at
TEFL Course Review. This is a site where TESL/TEFL courses and course providers are independently reviewed and rated.
Hope this helps