I imagine it would depend on your research question as to which approach was more appropriate. Larsson and Holmström (2007) discusses the two approaches in some detail. 10-15 participants is in ballpark for IPA - though smaller samples are feasible (even single case studies can be illuminating). Hope that helps!

Jan Larsson & Inger Holmström (2007) Phenomenographic or phenomenological analysis: does it matter? Examples from a study on anaesthesiologists’ work, International Journal of Qualitative Studies on Health and Well-being, 2:1, 55-64, DOI: 10.1080/17482620601068105

"Relatively permanent change in behavior that is the result of past experience or practice and acquisition of knowledge.; The research approach, developed within educational research, is a content-related approach investigating the different qualitative ways in which people develop an understanding of their environment." (sensagent.com)

IPA is based on phenomenology. This phenomenological framework's focus is on an individual’s perceptions (of experience or events or ideas) and the interpretative aspect, that means that the analyst in making sense of the individual’s personal experience (Smith, 2004). There are two types of interpretation in interpretative phenomenological analysis (the so-called ‘double hermeneutic’), as captured by Smith (2004, p. 40): “The participant is trying to make sense of their personal and social world; the researcher is trying to make sense (INTERPRETE) of the participants' personal and social world”

Interpretative Phenomenological Analysis | Pluralistic Psychology (wordpress.com)

As every science needs its own vocabulary the first belongs to education and the second to qualitative psychology stemming from health psychology.

Interpretive phenomenological analysis is a qualitative research approach that seeks to understand the meanings associated with lived experience. Today it is widely recognized and widely used in the field of psychology, especially in English-speaking countries; while phenomenography is a research approach that aims to identify and describe the qualitatively different ways in which people experience (understand, perceive) phenomena from their environment ... then, IN PART THEY ARE SIMILAR, BUT NOT IDENTICAL !:

In fact, phenomenography pretends to be, from the empirical science of learning, a replica of phenomenological analysis; but it tries to distance itself, at the same time, from both philosophy and psychology, while the IPA maintains close links with Phenomenological Philosophy and Psychology and, above all, Phenomenological Psychopathology (from Jasper et al.)

Hi

I uploaded three short presentations on my channel, I am sure they may be helpful to understand the difference and theoretical underpinning.

Phenomenology - IPA and Narrative Analysis

https://youtu.be/xU9S8aRL6ys

Interpretative Phenomenological Analysis - Theoretical roots

https://youtu.be/yeQPs6OrbtU

Interpretative Phenomenological Analysis - Mostackas, Coalizi, and Smith

https://youtu.be/5xTcUh_bnxE